Media: 3D Animation



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Selkirkia columbia

3D animation of Selkirkia columbia.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Unranked clade (stem group priapulids)
Species name: Selkirkia columbia
Remarks:

Selkirkia has been compared to the nemathelminth worms (Maas et al., 2007), but most analyses support a relationship with the priapulids at a stem-group level (Harvey et al., 2010; Wills, 1998).

Described by: Walcott
Description date: 1911
Etymology:

Selkirkia – from the Selkirk Mountains, a mountain range in southeastern British Columbia.

columbia – from British Columbia, where the Burgess Shale is located.

Type Specimens: Holotype –USNM57624 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: The genus Selkirkia ranges from the Lower to the Middle Cambrian and is represented by several species, including S. sinica from the Lower Cambrian Chengjiang Biota (Luo et al., 1999; Maas et al., 2007), S. pennsylvanica from the Lower Cambrian Kinzers Formation (Resser and Howell, 1938), Selkirkia sp. cf. and S. spencei from the Middle Cambrian Spence Shale of Utah (Resser, 1939; Conway Morris and Robison, 1986, 1988), and S. willoughbyi from the Middle Cambrian Marjum Formation of Utah (Conway Morris and Robison, 1986).

Age & Localities:

Age:
Middle Cambrian, Bathyuriscus-Elrathina Zone (approximately 505 million years ago).
Principal localities:

Burgess Shale and vicinity: The Walcott, Raymond and Collins Quarries on Fossil Ridge, and smaller localities on Mount Field and Mount Odaray. The Trilobite Beds, the Collins Quarry, the Tulip Beds (S7) and smaller localities on Mount Stephen.

Other deposits: The Middle Cambrian Spence Shale of Utah (Resser, 1939; Conway Morris and Robison, 1986, 1988).

History of Research:

Brief history of research:

Charles Walcott (1908) illustrated a single specimen of a simple tube that he named “Orthotheca major.” He interpreted the fossil as the tube of a polychaete worm, along with another famous species, “O. corrugata,” described by Matthew a decade earlier. O. corrugata is now referred to as Wiwaxia corrugata, which is not the tube of a worm but the scale of an armoured mollusc! The original specimen of “O. major” came from the Trilobite Beds on Mount Stephen, but it was not until the discovery of complete specimens from Fossil Ridge showing soft-bodied worms within the tubes that more details about this animal became available. Walcott (1911) created a new genus name Selkirkia to accommodate the new fossil material. In addition to the type species, S. major, he named two new species, S. gracilis and S. fragilis. In a revision of Walcott’s collections and other fossils discovered by the Geological Survey of Canada, Conway Morris (1977) synonymised Walcott’s three species into one that he called S. columbia, which is still in use today. S. columbia was described as a primitive priapulid worm (Conway Morris, 1977); later studies showed that it belongs to the priapulid stem group (Wills, 1998; Harvey et al., 2010).

Description:

Morphology:

Selkirkia lived in a tube and could reach up to 6 centimetres in length. The body of the worm itself is similar to most priapulids in having a trunk (which remained in the tube) and an anterior mouthpart that could be inverted into the trunk, called a proboscis. The proboscis has different series of spines along its length and is radially symmetrical. Small body extensions called papillae are present along the anterior part of the trunk and probably helped in anchoring the trunk in the tube. The gut is straight and the anus is terminal. The unmineralized tube is slightly tapered, open at both ends, and bears fine transverse lineations.

Abundance:

Selkirkia is the most abundant priapulid in the Walcott Quarry community, representing 2.7% of the entire community (Caron and Jackson, 2008); thousands of specimens are known, mostly isolated tubes.

Maximum Size:
60 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

The well developed proboscis and strong spines suggest a carnivorous feeding habit. Comparisons with modern tube-building priapulids suggest Selkirkia was capable of only limited movement, and spend most of the time buried vertically or at an angle to the sediment-water interface, where they might have “trap fed” on live prey. Empty tubes were often used as a substrate for other organisms to colonize, for example, brachiopods, sponges and primitive echinoderms (see Echmatocrinus).

References:

CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

CONWAY MORRIS, S. 1977. Fossil priapulid worms. Special Papers in Palaeontology, 20: 1-95.

CONWAY MORRIS, S. AND R. A. ROBISON. 1986. Middle Cambrian priapulids and other soft-bodied fossils from Utah and Spain. The University of Kansas paleontological contributions, 117: 1-22.

CONWAY MORRIS, S. AND R. A. ROBISON. 1988. More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia. University of Kansas Paleontological Contributions, Paper, 122: 23-48.

HARVEY, T. H. P., X. DONG AND P. C. J. DONOGHUE. 2010. Are palaeoscolecids ancestral ecdysozoans? Evolution & Development, 12(2): 177-200.

LUO, H., S. HU, L. CHEN, S. ZHANG AND Y. TAO. 1999. Early Cambrian Chengjiang fauna from Kunming region, China. Yunnan Science and Technology Press, Kunming, 162 p.

MAAS, A., D. HUANG, J. CHEN, D. WALOSZEK AND A. BRAUN. 2007. Maotianshan-Shale nemathelminths – Morphology, biology, and the phylogeny of Nemathelminthes. Palaeogeography, Palaeoclimatology, Palaeoecology, 254(1-2): 288-306.

RESSER, C. E. AND B. F. HOWELL. 1938. Lower Cambrian Olenellus Zone of the Appalachians. Geological Society of America, Bulletin, 49: 195-248.

RESSER, C. E. 1939. The Spence Shale and its fauna. Smithsonian Miscellaneous Collections, 97(12):1-29.

WALCOTT, C. 1908. Mount Stephen rocks and fossils. Canadian Alpine Journal, 1: 232-248.

WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-145.

WILLS, M. A. 1998. Cambrian and Recent disparity: the picture from priapulids. Paleobiology, 24(2): 177-199.

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Scenella amii

3D animation of Scenella amii.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Unranked clade (stem group molluscs)
Species name: Scenella amii
Remarks:

Scenella is generally classified as a monoplacophoran mollusc (Knight, 1952; Runnegar and Jell, 1976). A position possibly ancestral to brachiopods (Dzik, 2010), or within the Cnidaria, has also been proposed (Babcock and Robison, 1988; Yochelson and Gil Cid, 1984).

Described by: Matthew
Description date: 1902
Etymology:

Scenella – from the Greek word skene, “tent, or shelter,” in reference to its shape.

amii – after Marc Henri Ami from the Geological Survey of Canada.

Type Specimens: Holotype –ROM8048 in the Royal Ontario Museum, Toronto, ON, Canada.
Other species:

Burgess Shale and vicinity: none

Other deposits: Dozens of species are known from the Lower Cambrian to the Lower Ordovician.

Age & Localities:

Age:
Middle Cambrian, Bathyuriscus-Elrathina Zone (approximately 505 million years ago).
Principal localities:

The Walcott and Raymond Quarries on Fossil Ridge. The Trilobite Beds and smaller localities on Mount Stephen.

History of Research:

Brief history of research:

The limpet-like appearance of Scenella led to its original classification as a mollusc, initially as a pteropod, then as a gastropod (Walcott, 1886). The first fossils of this genus known from the Burgess Shale were collected from the Trilobite Beds on Mount Stephen. These were described as Metoptoma amii by Matthew (1902), but Walcott (1908) considered other specimens from the same locality (and from the Walcott Quarry) to belong to Scenella varians, an earlier named species. Resser (1938) recognized that both species were identical and proposed a new combination, Scenella amii. In the same publication, Resser named a second species from the Trilobite Beds S. columbiana; this was based on a single specimen, originally recognized as a brachiopod with possible spines (Walcott, 1912), and remains highly dubious.

Description:

Morphology:

Each cone-shaped fossil has the form of a flat disc with a central peak, here termed “shell.” Concentric rings surround this peak, and sometimes the shell is also corrugated. The shells are stretched along one axis, making them elliptical rather than circular.

The fossils are often preserved in dense clusters and are usually oriented point-up.

No soft tissue is ever found associated with Scenella. The shell was evidently mineralized as indicated by the three-dimensional preservation and the presence of small cracks suggesting brittleness.

Abundance:

Hundreds of specimens of S. amii are known in the Walcott Quarry (2.27% of the community, Caron and Jackson, 2008). Many of these are found in dense clusters on single slabs.

Maximum Size:
10 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

If a mollusc, Scenella would have been a creeping bottom-dweller, potentially a grazer.

References:

BABCOCK, L. E. AND R. A. ROBISON. 1988. Taxonomy and paleobiology of some Middle Cambrian Scenella (Cnidaria) and hyolithids (Mollusca) from western North America. University of Kansas Paleontological Contributions, Paper, 121: 1-22.

CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

DZIK, J. 2010. Brachiopod identity of the alleged monoplacophoran ancestors of cephalopods. Malacologia, 52:97-113.

KNIGHT, J. B. 1952. Primitive fossil gastropods and their bearing on gastropod evolution. Smithsonian Miscellaneous Collections, 117(13): 1–56.

MATTHEW, G. F. 1902. Notes on Cambrian Faunas: Cambrian Brachiopoda and Mollusca of Mt. Stephen, B.C. with the description of a new species of Metoptoma. Transactions of the Royal Society of Canada, 4:107-112.

RASETTI, F. 1954. Internal shell structures in the Middle Cambrian gastropod Scenella and the problematic genus Stenothecoides. Journal of Paleontology, 28: 59-66.

RESSER, C. E. 1938. Fourth contribution to nomenclature of Cambrian fossils. Smithsonian Miscellaneous Collections, 97:1-43.

Runnegar, B. AND P. A. JELL. 1976. Australian Middle Cambrian molluscs and their bearing on early molluscan evolution. Alcheringa: An Australasian Journal of Palaeontology, 1(2): 109-138.

WALCOTT, C. D. 1886. Second contribution to the studies on the Cambrian faunas of North America. Bulletin of the United States Geological Survey, (30): 11-356.

WALCOTT, C. 1908. Mount Stephen rocks and fossils. Canadian Alpine Journal, 1: 232-248.

WALCOTT, C. 1912. Cambrian Brachiopoda. United States Geological Survey Monograph, 51: Part 1: 1-872, Part 872: 871-363.

YOCHELSON, E. L. AND D. GIL CID. 1984. Reevaluation of the systematic position of Scenella. Lethaia, 17: 331-340.

Other Links:

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Isoxys acutangulus

3D animation of Isoxys carinatus.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Family Isoxyidae
Species name: Isoxys acutangulus
Remarks:

Isoxys is included with Surusicaris in the family isoxyidae, based on the type of carapace, eyes, and frontal pair of raptorial appendages (Aria & Caron, 2015). Current evidence draws out a consensus among authors placing isoxyids as sister taxa to true arthropods (Edgecombe, 2020; Aria, 2022), although it is not clear whether Surusicaris and Isoxys are part of a single separate lineage (that is, form a monophyletic group). However, key characters such as the segmentation of the trunk and trunk appendages are still being investigated.

Described by: Walcott
Description date: 1908
Etymology:

Isoxys – from the Greek isos, “equal,” and xystos, “smooth surface”; thus referring to the pair of smooth valves.

acutangulus – from the Latin acutus, “sharp, pointed,” and angulus, “angle”; thus referring to the acute angle of the cardinal spines.

Type Specimens: USNM56521 (I. acutangulus) and Holotype –USNM189170 (I. longissimus) in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: I. longissimus from Walcott, Raymond and Collins Quarries on Fossil Ridge.

Other deposits: I. chilhoweanus from the Chilhowee Group, Tennessee, USA; I. auritus, I. paradoxus and I. curvirostratus from the Maotianshan Shale of China; I. bispinatus from the Shuijingtuo Formation, Hubei, China; I. wudingensis from the Guanshan fauna of China; I. communis and I. glaessneri from the Emu Bay Shale of Australia; I. volucris from the Buen Formation, Sirius Passet in Greenland; I. carbonelli from the Sierro Morena of Spain, and I. zhurensis from the Profallotaspis jakutensis Zone of Western Siberia. Undescribed species from Canada; Mount Cap Formation in the Mackenzie Mountains, Northwest Territories and the Eager Formation near Cranbrook. Other undescribed species in the Kaili Formation, Guizhou Province, China and the Kinzers Formation, Pennsylvania, USA. See references in Briggs et al. (2008), García-Bellido et al. (2009b; 2009a), Stein et al. (2010), Vannier and Chen (2000).

Age & Localities:

Age:
Middle Cambrian, Wuliuan Stage, upper part of the Burgess Shale Formation (around 505 million years old).
Principal localities:

The Walcott, Raymond and Collins Quarries on Fossil Ridge. Additional localities are known on Mount Field, Mount Stephen – the Tulip Beds (S7), the Trilobite Beds, near Stanley Glacier and across Marble Canyon localities, Kootenay National Park, British Columbia.

History of Research:

Brief history of research:

Walcott gave the name Isoxys to specimens from the lower Cambrian Chilhowee Group of Tennessee, USA, in 1890. He then later designated the first species from the Trilobite Beds on Mount Stephen, Anomalocaris? acutangulus (Walcott, 1908), erroneously placing it within the genus Anomalocaris. Simonetta and Delle Cave (1975) renamed it Isoxys acutangulus and discovered a second Burgess Shale species, I. longissimus. The original designations were based on carapaces only, making research on the ecology and affinity of Isoxys difficult. Since then, eyes, appendages and tailpiece have been described (García-Bellido et al., 2009b; Vannier et al., 2009; Fu, Zhang & Shu, 2011; Legg & Vannier, 2013; Fu et al., 2014). Trunk appendages seem atypical, with broad attachment of outer and inner branches—as in Surusicaris—and close contact of paired inner branches, which has been further illustrated in the related form Erratus sperare (Fu et al., 2022). Sexual dimorphism has also been proposed in Isoxys volucris based on the relative width of the doublure (Nielsen, Rasmussen & Harper, 2017).

Description:

Morphology:

The most prominent feature of Isoxys is the non-biomineralized carapace, which ranged in length from 1 cm to almost 4 cm, and covered most of the body. It was folded to give two equal hemispherical valves, and had pronounced spines at the front and back. A pair of bulbous, spherical eyes protrudes forward and laterally from under the carapace. They are attached to the head by very short stalks. A pair of frontal appendages that are segmented and non-branching (uniramous) is adjacent to the eyes. In I. acutangulus, the flexible appendages are curved with a serrated outline and five segments in total, including a basal part, three segments with stout outgrowths, and a pointed terminal segment. The trunk of the body has 13 pairs of evenly spaced appendages that are segmented and branch into two (biramous), with slender limbs and large, paddle-like flaps fringed with long setae. Outer and inner branches are broadly attached at their base, and pairs of inner branches also seem bound together. The tailpiece would be a tailfan, as in dinocaridids (Legg & Vannier, 2013). A cylindrical gut passes from the head to the ventral terminus of the telson, and is lined dorsally by large concatenate, triangular gut glands. I. longissimus is distinguished from I. acutangulus by the presence of extremely long spines and an elongate body shape.

Abundance:

Isoxys is known from hundreds of specimens collected on Fossil Ridge. In the Walcott Quarry, Isoxys acutangulus is relatively common and represents about 0.35% of the community whereas Isoxys longissimus is extremely rare (Caron and Jackson, 2008).

Maximum Size:
About 40 mm.

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

The streamlined body, thin carapace, the presence of paddle-shaped flaps in the appendages and a flap-bearing tailfan all suggest that Isoxys was a free-swimming animal. A predatory lifestyle is indicated by the large eyes, frontal appendage, and large gut glands. Isoxys would have swum just above the sea floor, seeking out prey in the water column and at the sediment-water interface. Isoxys is commonly found among benthic/nektobenthic assemblages (Caron & Jackson, 2008) and possess general morphological characteristics of other nektobenthic Cambrian arthropods.

References:

  • ARIA, C. (2022) The origin and early evolution of arthropods. Biological Reviews 97, 1786–1809.
  • ARIA, C. & CARON, J.-B. (2015) Cephalic and limb anatomy of a new isoxyid from the Burgess Shale and the role of ‘stem bivalved arthropods’ in the disparity of the frontalmost appendage. PLoS ONE 10, e0124979.
  • BRIGGS, D.E.G., LIEBERMAN, B.S., HENDRICKS, J.R., HALGEDAHL, S.L. & JARRARD, R.D. (2008) Middle Cambrian arthropods from Utah. J Paleontol 82, 238–254.
  • CARON, J.B. & JACKSON, D.A. (2008) Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology 258, 222–256.
  • EDGECOMBE, G.D. (2020) Arthropod origins: Integrating paleontological and molecular evidence. Annual Review of Ecology, Evolution, and Systematics 51, 1–25.
  • FU, D., LEGG, D.A., DALEY, A.C., BUDD, G.E., WU, Y. & ZHANG, X. (2022) The evolution of biramous appendages revealed by a carapace-bearing Cambrian arthropod. Philosophical Transactions of the Royal Society B: Biological Sciences 377, 20210034.
  • FU, D., ZHANG, X., BUDD, G.E., LIU, W. & PAN, X. (2014) Ontogeny and dimorphism of Isoxys auritus (Arthropoda) from the Early Cambrian Chengjiang biota, South China. Gondwana Research 25, 975–982.
  • FU, D.J., ZHANG, X.L. & SHU, D.G. (2011) Soft anatomy of the Early Cambrian arthropod Isoxys curvirostratus from the Chengjiang biota of South China with a discussion on the origination of great appendages. Acta Palaeontologica Polonica 56, 843–852.
  • GARCÍA-BELLIDO, D.C., PATERSON, J.R., EDGECOMBE, G.D., JAGO, J.B., GEHLING, J.G. & LEE, M.S.Y. (2009a) The bivalved arthropods Isoxys and Tuzoia with soft-part preservation from the Lower Cambrian Emu Bay Shale Lagerstätte (Kangaroo Island, Australia). Palaeontology 52, 1221–1241.
  • GARCÍA-BELLIDO, D.C., VANNIER, J. & COLLINS, D. (2009b) Soft-part preservation in two species of the arthropod Isoxys from the middle Cambrian Burgess Shale of British Columbia, Canada. Acta Palaeontologica Polonica 54, 699–712.
  • LEGG, D.A. & VANNIER, J. (2013) The affinities of the cosmopolitan arthropod Isoxys and its implications for the origin of arthropods. Lethaia 46, 540–550.
  • NIELSEN, M.L., RASMUSSEN, J.A. & HARPER, D.A.T. (2017) Sexual dimorphism within the stem-group arthropod Isoxys volucris from the Sirius Passet Lagerstätte, North Greenland. Bulletin of the Geological Society of Denmark 65, 47–58.
  • STEIN, M., PEEL, J.S., SIVETER, D.J. & WILLIAMS, M. (2010) Isoxys (Arthropoda) with preserved soft anatomy from the Sirius Passet Lagerstätte, lower Cambrian of North Greenland. Lethaia 43, 258–265.
  • VANNIER, J. & CHEN, J.Y. (2000) The Early Cambrian colonization of pelagic niches exemplified by Isoxys (Arthropoda). Lethaia 33, 295–311.
  • VANNIER, J., GARCÍA-BELLIDO, D.C., HU, S.X. & CHEN, A.L. (2009) Arthropod visual predators in the early pelagic ecosystem: evidence from the Burgess Shale and Chengjiang biotas. Proceedings of the Royal Society of London Series B 276, 2567–2574.
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Hurdia victoria

3D animation of Hurdia victoria.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Radiodonta, Family Hurdiidae
Species name: Hurdia victoria
Remarks:

With its single pair of jointed frontal appendages, lateral swimming flaps, and circular mouth structure, Hurdia possesses all the hallmarks of Radiodonta, part of the stem group to the true arthropods which also includes the iconic Anomalocaris (Collins, 1996). It is the namesake of the radiodontan family Hurdiidae, characterized by frontal appendages with comb or rake-like inner spines (Lerosey-Aubril & Pates, 2018). Hurdia is part of a diverse subgroup of hurdiids with large, elaborate carapaces (Caron & Moysiuk, 2021).

Described by: Walcott
Description date: 1912
Etymology:

Hurdia – from Mount Hurd (2,993 m), a mountain northeast of the now defunct Leanchoil railway station on the Canadian Pacific Railway in Yoho National Park. The peak was named by Tom Wilson for Major M. F. Hurd, a CPR survey engineer who explored the Rocky Mountain passes starting in the 1870s.

victoria – unspecified; perhaps from Mount Victoria (3,464 m) on the border of Yoho and Banff National Parks, named by Norman Collie in 1897 to honour Queen Victoria.

Type Specimens: Lectotypes –USNM57718 (H. victoria) andUSNM57721 (H. triangulata) in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: Hurdia triangulata.

Other deposits: Potentially other species are represented in the Langston and Wheeler Formations of Utah (Lerosey-Aubril et al., 2020; Pates et al., 2018), and possibly the Pioche Formation of Nevada (Pates, Daley, Edgecombe, et al., 2019), the Jince Formation in the Czech Republic (Chlupáč & Kordule, 2002). and the Shuijingtuo Formation in Hubei Province, China (Cui & Huo, 1990).

Age & Localities:

Age:
Middle Cambrian, Wuliuan Stage, Burgess Shale Formation (around 505 million years old).
Principal localities:

The Walcott, Raymond, and Collins Quarries on Fossil Ridge. Also known from other localities on Mount Field, Mount Stephen – Tulip Beds (S7) – and near Stanley Glacier and the Monarch.

History of Research:

Brief history of research:

Although isolated parts of the body of Hurdia were first identified in the early 1900s, no affinity could be determined until the description of whole-body specimens by Daley et al. in 2009. Hurdia victoria was the name originally given to an isolated triangular carapace that Walcott (1912) suggested belonged to an unknown arthropod. Proboscicaris, another isolated carapace, was originally described as a crustacean (Rolfe, 1962). Hurdia’s frontal appendages were first described by Walcott (1911b) as the feeding limbs of Sidneyia, but were later removed from this genus and referred to as “Appendage F” with unknown affinity (Briggs, 1979). Like other radiodontans, the mouthparts were first described as the jellyfish Peytoia nathorsti (Walcott, 1911a). Whittington and Briggs (1985) discovered the first whole body specimens of Peytoia, associating the mouthparts with the former “Appendage F”. When describing Peytoia and Anomalocaris, Whittington and Briggs (1985) also figured a mouth apparatus with extra rows of teeth.

After two decades of collecting at the Burgess Shale, Desmond Collins from the Royal Ontario Museum (ROM) discovered that this extra-spiny mouth part actually belonged to a third type of radiodontan, which also had an “Appendage F” pair and a frontal carapace complex consisting of one Hurdia carapace and two Proboscicaris carapaces (Daley et al., 2009). This is the Hurdia animal. ROM specimens of “Appendage F” showed that it has four distinct morphologies, two of which belong to Hurdia (known from two species, H. victoria and H. triangulata), one to Peytoia nathorsti, and one to an as yet unnamed species (Daley et al., 2013; Daley & Budd, 2010).

Description:

Morphology:

Hurdia has a bilaterally symmetrical body that is broadly divisible into two sections of equal lengths. The anterior region is a complex of non-biomineralized carapaces consisting of one dorsal triangular H-element (previously called Hurdia) and two lateral paddle-shaped P-elements (from Proboscicaris). These carapaces wrap around the anterior margin of the head with the H-element spine protruding forward. The surfaces of the H- and P-elements are covered in a distinctive polygonal pattern similar to that seen on Tuzoia carapaces. A pair of oval eyes on short stalks protrudes upwards through notches in the overlapping posterior corners of the H- and P-elements. Hurdia triangulata differs from Hurdia victoria by having a wider and shorter H-element (Daley et al., 2013). Mouthparts are on the ventral surface of the head, and consist of a circlet of 32 tapering and overlapping plates, 4 large and 28 small, with spines lining the square central opening. Within the central opening are up to five inner rows of toothed plates. A pair of appendages flanks the mouth part, each with nine thin segments with short outer spines and eight elongated ventral spines (Daley et al., 2013; Pates, Daley, & Butterfield, 2019). The posterior half of the body consists of a series of seven to nine segments that extend laterally into triangular flaps. Recently, Van Roy and colleagues (2015) suggested that a second row of flaps might also be present in Hurdia. Each body segment is associated with a band of elongated blades interpreted to be gill structures. The body terminates abruptly in two rounded lobes (Daley et al., 2013). Complete specimens are up to 20 cm in length, although disarticulated fragments suggest a maximum body size up to 30 cm long (Caron & Moysiuk, 2021).

Abundance:

Over 700 specimens of Hurdia have been identified, most of which are disarticulated. Hurdia is found in all Burgess Shale quarries on Fossil Ridge, and is particularly abundant in Raymond Quarry, where it makes up almost 1% of the community (240 specimens). A total of 7 complete body specimens exist.

Maximum Size:
300 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

Hurdia was likely an active swimmer. Like other radiodontans, the animal propelled itself through the water column by undulating its flaps (Usami, 2006) and respiration would have been accomplished through the multiple rows of gills (Daley et al., 2013). The large dorsal carapace, upward facing eyes, and stubby body suggest it spent most of its time near the sea floor and may have fed primarily on burrowing organisms (Moysiuk & Caron, 2019). The function of the frontal carapace remains unknown, although it has been speculated to have played a role in feeding (Caron & Moysiuk, 2021; Daley et al., 2013). Prey items were funneled towards the mouth by a sweeping motion of the of the frontal appendages, with their rake-like inner spines forming a rigid net or cage (de Vivo et al., 2021; Moysiuk & Caron, 2019). Compared to Cambroraster and Titanokorys, the widely spaced spines on Hurdia’s appendages suggest it fed on relatively larger prey items (Caron & Moysiuk, 2021).

References:

  • BRIGGS, D. E. G. (1979). Anomalocaris: The largest known Cambrian arthropod. Palaeontology, 22(3), 631–664.
  • CARON, J.-B., & MOYSIUK, J. (2021). A giant nektobenthic radiodont from the Burgess Shale and the significance of hurdiid carapace diversity. Royal Society Open Science, 8(9), 210664. https://doi.org/10.1098/RSOS.210664
  • CHLUPÁČ, I., & KORDULE, V. (2002). Arthropods of Burgess Shale type from the Middle Cambrian of Bohemia (Czech Republic). Bulletin of the Czech Geological Survey, 77, 167–182.
  • COLLINS, D. (1996). The “evolution” of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.). Journal of Paleontology, 70(2), 280–293. https://doi.org/10.1017/S0022336000023362
  • CUI, Z.-L., & HUO, S.-C. (1990). New discoveries of Lower Cambrian crustacean fossils from western Hubei. Acta Palaeontologica Sinica, 29, 321–330.
  • DALEY, A. C., & BUDD, G. E. (2010). New anomalocaridid appendages from the Burgess Shale, Canada. Palaeontology, 53(4), 721–738. https://doi.org/10.1111/j.1475-4983.2010.00955.x
  • DALEY, A. C., BUDD, G. E., & CARON, J.-B. (2013). Morphology and systematics of the anomalocaridid arthropod Hurdia from the Middle Cambrian of British Columbia and Utah. Journal of Systematic Palaeontology, 11(7), 743–787. https://doi.org/10.1080/14772019.2012.732723
  • DALEY, A. C., BUDD, G. E., CARON, J.-B., EDGECOMBE, G. D., & COLLINS, D. (2009). The Burgess Shale anomalocaridid Hurdia and its significance for early euarthropod evolution. Science, 323(5921), 1597–1600. https://doi.org/10.1126/science.1169514
  • DE VIVO, G., LAUTENSCHLAGER, S., & VINTHER, J. (2021). Three-dimensional modelling, disparity and ecology of the first Cambrian apex predators. Proceedings of the Royal Society B, 288(1955). https://doi.org/10.1098/RSPB.2021.1176
  • LEROSEY-AUBRIL, R., KIMMIG, J., PATES, S., SKABELUND, J., WEUG, A., & ORTEGA-HERNÁNDEZ, J. (2020). New exceptionally preserved panarthropods from the Drumian Wheeler Konservat-Lagerstätte of the House Range of Utah. Papers in Palaeontology, 6(4), 501–531. https://doi.org/10.1002/spp2.1307
  • LEROSEY-AUBRIL, R., & PATES, S. (2018). New suspension-feeding radiodont suggests evolution of microplanktivory in Cambrian macronekton. Nature Communications, 9(1), 3774. https://doi.org/10.1038/s41467-018-06229-7
  • MOYSIUK, J., & CARON, J.-B. (2019). A new hurdiid radiodont from the Burgess Shale evinces the exploitation of Cambrian infaunal food sources. Proceedings of the Royal Society B, 286(1908), 20191079. https://doi.org/10.1098/rspb.2019.1079
  • PATES, S., DALEY, A. C., & BUTTERFIELD, N. J. (2019). First report of paired ventral endites in a hurdiid radiodont. Zoological Letters, 5(1), 18. https://doi.org/10.1186/s40851-019-0132-4
  • PATES, S., DALEY, A. C., EDGECOMBE, G. D., CONG, P., & LIEBERMAN, B. S. (2019). Systematics, preservation and biogeography of radiodonts from the southern Great Basin, USA, during the upper Dyeran (Cambrian Series 2, Stage 4). Papers in Palaeontology, 7(1), 235–262. https://doi.org/10.1002/spp2.1277
  • PATES, S., DALEY, A. C., & LIEBERMAN, B. S. (2018). Hurdiid radiodontans from the middle Cambrian (Series 3) of Utah. Journal of Paleontology, 92(1), 99–113. https://doi.org/10.1017/jpa.2017.11
  • ROLFE, W. D. (1962). Two new arthropod carapaces from the Burgess Shale (Middle Cambrian) of Canada. Breviora Museum of Comparative Zoology, 60, 1–9.
  • USAMI, Y. (2006). Theoretical study on the body form and swimming pattern of Anomalocaris based on hydrodynamic simulation. Journal of Theoretical Biology, 238, 11–17.
  • VAN ROY, P., DALEY, A. C., & BRIGGS, D. E. G. (2015). Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps. Nature, 522(7554), 77. https://doi.org/10.1038/nature14256
  • WALCOTT, C. D. (1911a). Middle Cambrian holothurian and medusae. Smithsonian Miscellaneous Collections, 57, 41–68.
  • WALCOTT, C. D. (1911b). Middle Cambrian Merostomata. Cambrian Geology and Paleontology II. Smithsonian Miscellaneous Collections, 57, 17–40.
  • WALCOTT, C. D. (1912). Middle Cambrian Branchiopoda, Malacostraca, Trilobita and Merostomata. Smithsonian Miscellaneous Collections, 57, 145–228.
  • WHITTINGTON, H. B., & BRIGGS, D. E. G. (1985). The largest Cambrian animal, Anomalocaris, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society B: Biological Sciences, 309(1141), 569–609. https://doi.org/10.1098/rstb.1985.0096
Other Links:

http://www.sciencemag.org/content/323/5921/1597.abstract



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Hazelia palmata

3D animation of Hazelia conferta and other sponges (Choia ridleyi, Diagoniella cyathiformis, Eiffelia globosa, Pirania muricata, Vauxia bellula, and Wapkia elongata) and Chancelloria eros a sponge-like form covered of star-shaped spines.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Demospongea (Order: Monaxonida)
Species name: Hazelia palmata
Remarks:

Hazelia is considered a primitive demosponge, close to Falospongia and Crumillospongia (Rigby, 1986). Demosponges, the same group that are harvested as bath sponges, represent the largest class of sponges today.

Described by: Walcott
Description date: 1920
Etymology:

Hazelia – from Hazel Peak (3,151 m), the older name for Mount Aberdeen, located 4 km SSW of Lake Louise in Banff National Park, Alberta. Mount Aberdeen was named in honor of Lord Gordon in 1897, the Marquis of Aberdeen and the Governor General of Canada from 1893 to 1898.

palmata – from the Latin palm, “palm of the hand,” referring to the broad cup-shape of this sponge and its resemblance to a cupped hand.

Type Specimens: Lectotypes – USNM 66463 (H. palmata – type species), 66465 (H. delicatula), USNM 66505 (H. dignata), USNM 66473 (H. grandis), USNM 66474 (H. nodulifera), USNM 66472 (H. obscura); Holotypes – USNM 66476 (H. conferta), USNM 66779 (H. crateria), USNM 66475 (H. luteria) in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. Holotype –ROM53573 (H. lobata) in the Royal Ontario Museum, Toronto, Canada.
Other species:

Burgess Shale and vicinity: H. conferta Walcott, 1920, H. crateria Rigby, 1986, H. delicatula Walcott, 1920, H. dignata Walcott, 1920, H. grandis Walcott, 1920, H. lobata Rigby and Collins, 2004, H. luteria Rigby, 1986, H. nodulifera Walcott, 1920, H. obscura Walcott, 1920. Most species known from the Walcott Quarry (See Rigby, 1986 and Rigby and Collins, 2004).

Other deposits: H. walcotti (Resser and Howell, 1938) from the Early Cambrian Kinzers Formation of Pennsylvania (See Rigby, 1987).

Age & Localities:

Age:
Middle Cambrian, Bathyuriscus-Elrathina Zone to Bolaspidella Zone (approximately 505 million years ago).
Principal localities:

Burgess Shale and vicinity: Hazelia is particularly common in the Walcott Quarry and is less common in the Raymond and Collins Quarries on Fossil Ridge. Many species also occur on Mount Stephen at the Trilobite Beds, Tulip Beds (S7), and other smaller localities.

Other deposits: H. palmata Walcott, 1920 from the Middle Cambrian Marjum Formation (Rigby et al., 1997).

History of Research:

Brief history of research:

Walcott described seven species of Hazelia in his 1920 paper on the Burgess Shale sponges. The genus was redescribed by Rigby in 1986 when two new species were added and one excluded from the genus (H. mammillata now referred to Moleculospina mammillata). Rigby and Collins (2004) added another species based on new material collected by the Royal Ontario Museum.

Description:

Morphology:

Species of Hazelia have a large variation in morphology with wide cup-shaped forms (H. palmata, H. crateria, H. luteria), long cone-shaped forms (H. conferta, H. grandis, H. obscura), branched forms (H. delicatula, H. dignata), and nodular to lobate forms (H. lobata, H. nodulifera). While there is this significant variety of overall shapes, the different species of Hazelia have a common microstructure. The walls are thin and composed of small tightly packed simple spicules that form a net-like structure and diverge outwards producing a plumose pattern. The walls are perforated with small canals to allow water flow. The base of each sponge would have had a small attachment structure.

In addition to its open shield-like shape, H. palmata possesses distinct radial tracts of spicules which go beyond the margins of the sponge for at least a couple of millimeters.

Abundance:

Hazelia is very common in the Walcott Quarry and represents 9.5% of the community (Caron and Jackson, 2008).

Maximum Size:
150 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

Hazelia would have lived attached to the sea floor. Particles of organic matter were extracted from the water as they passed through canals in the sponge’s wall.

References:

CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

RIGBY, J. K. 1986. Sponges of the Burgess Shale (Middle Cambrian), British Columbia. Palaeontographica Canadiana, 2: 105 p.

RIGBY, J. K. 1987. Early Cambrian sponges from Vermont and Pennsylvania, the only ones described from North America. Journal of Paleontology, 61: 451-461.

RIGBY, J. K. L. F. GUNTHER AND F. GUNTHER. 1997. The first occurrence of the Burgess Shale Demosponge Hazelia palmata Walcott, 1920, in the Cambrian of Utah. Journal of Paleontology, 71: 994-997.

RIGBY, J. K. AND D. COLLINS. 2004. Sponges of the Middle Cambrian Burgess Shale and Stephen Formations, British Columbia. Royal Ontario Museum Contributions in Science (1): 155 p.

WALCOTT, C. D. 1920. Middle Cambrian Spongiae. Cambrian Geology and Paleontology IV. Smithsonian Miscellaneous Collections, 67(6): 261-365.

Other Links:

None



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Haplophrentis carinatus

3D animation of Haplophrentis carinatus.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Hyolitha (Order: Hyolithida, stem group molluscs)
Species name: Haplophrentis carinatus
Remarks:

Haplophrentis belongs to a group of enigmatic cone-shaped to tubular fossils called hyoliths that are known only from the Palaeozoic. Their taxonomic position is uncertain, but the Hyolitha have been regarded as a separate phylum, an extinct Class within Mollusca (Malinky and Yochelson, 2007), or as stem-group molluscs.

Described by: Matthew
Description date: 1899
Etymology:

Haplophrentis – from the Greek haploos, “single,” and phrentikos, “wall,” in reference to the single wall within the shell.

carinatus – from the Latin carinatus, “keel-shaped,” referring to the morphological similarity to the bottom of a boat.

Type Specimens: Lectotype –ROM8463a in the Royal Ontario Museum, Toronto, Canada.
Other species:

Burgess Shale and vicinity: none

Other deposits: H. reesei Babcock & Robinson, 1988 (type species), from the lower Middle Cambrian Spence Shale and elsewhere in Utah; H.? cf. carinatus from the Middle Cambrian Kaili deposit in China (Chen et al., 2003).

Age & Localities:

Age:
Middle Cambrian, Albertella Zone to Bathyuriscus-Elrathina Zone (approximately 505 million years ago).
Principal localities:

The Walcott, Raymond and Collins Quarries on Fossil Ridge, the Trilobite Beds on Mount Stephen and Stanley Glacier in Kootenay National Park.

History of Research:

Brief history of research:

Matthew described Hyolithes carinatus from the Trilobite Beds in 1899 based on five incomplete specimens. Babcock and Robison (1988) reviewed the original fossils, along with additional specimens collected by the Royal Ontario Museum from various Burgess Shale localities. They concluded that the species carinatus didn’t belong in Hyolithes, and established a new genus, Haplophrentis, to accommodate it.

Description:

Morphology:

Like all hyoliths, Haplophrentis had a weakly-mineralized skeleton that grew by accretion, consisting of a conical living shell (conch), capped with a clam-like “lid” (operculum), with two slender, curved and rigid structures known as “helens” protruding from the shell’s opening. The function of these helens is still debated, but one possibility was to allow settlement and stabilization on the sea floor. Haplophrentis had a wiggly gut whose preserved contents are similar to the surrounding mud.

H. carinatus usually grew to around 25 mm in length, although some specimens reached as much as 40 mm; the species is distinguished from H. reesei, its cousin from Utah, by the faint grooves on its upper surface, the more pronounced net-like pattern on its “lid” (operculum), and its wider, more broadly-angled living shell (conch).

Haplophrentis can be distinguished from the similar hyolith genus Hyolithes because it bears a longitudinal wall running down the inner surface of the top of its living-shell.

Abundance:

Haplophrentis is relatively common on Fossil Ridge and in the Walcott Quarry in particular, accounting for 0.35% of the community there (Caron and Jackson, 2008).

Maximum Size:
40 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

Haplophrentis probably moved very little; its helens appear unsuited for use in locomotion (See Butterfield and Nicholas, 1996; Martí Mus and Bergström, 2005; Runnegar et al., 1975). Whilst Haplophrentis feeding mode remains somewhat conjectural, it probably consumed small organic particles from the seafloor. Numerous specimens have been found in aggregates or in the gut of the priapulid worm Ottoia prolifica suggesting Haplophrentis was actively preyed upon and ingested (Conway Morris, 1977; Babcock and Robison, 1988).

References:

BABCOCK, L. E. AND R. A. ROBISON. 1988. Taxonomy and paleobiology of some Middle Cambrian Scenella (Cnidaria) and hyolithids (Mollusca) from western North America. University of Kansas Paleontological Contributions, Paper, 121: 1-22.

BUTTERFIELD, N. J. AND C. NICHOLAS. 1996. Burgess Shale-type preservation of both non-mineralizing and “shelly” Cambrian organisms from the Mackenzie Mountains, Northwestern Canada. Journal of Paleontology, 70: 893-899.

CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

CHEN, X. Y. ZHAO AND P. WANG. 2003. Preliminary research on hyolithids from the Kaili Biota, Guizhou. Acta Micropalaeontologica Sinica, 20: 296-302.

CONWAY MORRIS, S. 1977. Fossil priapulid worms. Special Papers in Palaeontology, 20: 1-95.

MALINKY, J. M. AND E. L. YOCHELSON. 2007. On the systematic position of the Hyolitha (Kingdom Animalia). Memoir of the Association of Australasian Palaeontologists, 34: 521-536.

MARTÍ MUS, M. AND J. BERGSTRÖM. 2005. The morphology of hyolithids and its functional implications. Palaeontology, 48:1139-1167.

MATTHEW, G. F. 1899. Studies on Cambrian faunas, No. 3. Upper Cambrian fauna of Mount Stephen, British Columbia. The trilobites and worms. Transactions of the Royal Society of Canada, Series 2, 4: 39-66.

RUNNEGAR, B., J. POJETA, N. J. MORRIS, J. D. TAYLOR, M. E. TAYLOR AND G. MCCLUNG. 1975. Biology of the Hyolitha. Lethaia, 8: 181-191.

Other Links:

http://paleobiology.si.edu/burgess/haplophrentis.html

http://www.kumip.ku.edu/cambrianlife/Utah-Mollusks-Hyolithids.html



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Hallucigenia sparsa

3D animation of Hallucigenia sparsa.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Family Hallucigeniidae
Species name: Hallucigenia sparsa
Remarks:

Hallucigenia is one of a variety of lobopodian taxa from the Cambrian, which are early members of the lineage that gave rise to arthropods, and whose only modern survivors are onychophorans (velvet worms) and tardigrades (water bears). Lobopodians characteristically have annulated, unjointed bodies and bear soft limbs after which they are called: the lobopods. Hallucigenia defines the family Hallucigeniidae, which includes other “tentacular” lobopodians with dorsal plates or spines. Hallucigeniidae are found to be basal lobopodians by some (Caron & Aria 2017, 2020), or allied with onychophorans by others (Smith & Ortega-Hernandez 2014; Yang et al. 2015201; Howard et al. 2020).

Described by: Walcott
Description date: 1911
Etymology:

Genus – from the Latin hallucinatus, “wandering of the mind,” after the bizarreness of the animal. The origin of the suffix is unclear, but perhaps -genus, “sprung from”.

species – from the Latin sparsus, “rare, or scattered,” reflecting the rarity of the specimens available in the original study.

Type Specimens: Holotype –USNM83935 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: None.

Other deposits: H. fortis from the early Cambrian Stage 3 Chengjiang biota (Hou & Bergström 1995) and H. hongmeia from the early Cambrian Stage 4 Guanshan biota (Steiner et al. 2012).

Age & Localities:

Age:
Middle Cambrian, Wuliuan stage, Burgess Shale Formation (approximately 505 million years ago).
Principal localities:

The Walcott and Raymond Quarries on Fossil Ridge. The Tulip Beds (S7) on Mount Stephen.

History of Research:

Brief history of research:

Hallucigenia was originally described as “Canadia sparsa” by Walcott (1911) in a review of various Burgess Shale “annelids.” One specimen was illustrated twenty years later (Walcott 1931), but the first thorough study of this animal wasn’t published until Conway Morris (1977) demonstrated that it did not belong to the genus Canadia or to the annelids at all. His reconstruction showed a bizarre animal walking on spines, with dorsal tentacles interpreted as a feeding apparatus (Conway Morris 1977). The new genus name Hallucigenia was coined in reference to this “dreamlike” appearance and also reflected the organism’s uncertain affinities. It was later shown that the supposed tentacles represented just one row of paired “legs” – the others were buried under a layer of rock and the paired spines were on the dorsal surface (Ramsköld & Hou 1991; Ramsköld 1992). The anteroposterior orientation was also reversed, with the former head interpreted as possible decay fluids seeping from the body (Ramsköld 1992). It was later pointed out that hallucigeniid spines were geographically widespread, and were found from the Terreneuvian (early Cambrian) to through the Wuliuan (middle Cambrian) (Caron et al. 2013). These spines display a “cone-in-cone” growth structure comparable to the sclerotic elements of modern onychophorans (Smith & Ortega-Hernandez 2014), a condition now shown to be ancestral in lobopodians (Caron & Aria 2020). Hallucigenia sparsa was finally redescribed in full by Smith and Caron (2015), who documented the presence of eyes and of a ring of plates inside the mouth.

Description:

Morphology:

Hallucigenia has a worm-like body with a small head at the end of a long neck, which bears three pairs of very thin, “tentacle”-like lobopods; the trunk bears seven pairs of long dorsal spines covering the last pair of tentacles and 6 pairs of somewhat stouter but still elongate limbs, ending in strong claws. The rear-most pair of legs does not have a corresponding pair of spines above. The spines are embedded inside skin “sheaths” on the dorsal side of the animal. The head is slightly swollen and bears a pair of simple dorsal eyes as well as a terminal mouth. Around the pharyngeal opening is a ring of many small plates, and the pharyngeal wall itself is lined with a multitude of small teeth.

Abundance:

The redescription by Conway Morris (1977) was based on about 30 specimens, but 132 were later studied by Smith and Caron (Smith & Caron 2015). Overall, Hallucigenia is rare, and in the Walcott Quarry it represents 0.19% of the specimens counted in the community (Caron and Jackson, 2008).

Maximum Size:
30 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

Hallucigenia is often found in association with the sponge Vauxia and other organic debris. This co-occurrence has led to suggestions that Hallucigenia fed on sponges, using its clawed legs to hang on, with its spines protecting it from predation. Recently, morphological characteristics—including the frontal tentacles, as well as long, slender lobopods in association with stout claws—have prompted the proposition that Hallucigenia and its relatives were suspension feeders (Caron & Aria 2017), which would have then used sponges as substrate to stand erect in the water column.

References:

  • CARON, J. and ARIA, C. 2020. The Collins’ monster, a spinous suspension‐feeding lobopodian from the Cambrian Burgess Shale of British Columbia. Palaeontology, 63, 979–994.
  • CARON, J. B., SMITH, M. and HARVEY, T. H. P. 2013. Beyond the Burgess Shale: Cambrian microfossils track the rise and fall of hallucigeniid lobopodians. Proceedings of the Royal Society B: Biological Sciences, 280, 20131613.
  • CARON, J.-B. and ARIA, C. 2017. Cambrian suspension-feeding lobopodians and the early radiation of panarthropods. BMC Evolutionary Biology, 17, 29.
  • CONWAY MORRIS, S. 1977. A new metazoan from the Cambrian Burgess Shale of British Columbia. Palaeontology, 20, 623–640.
  • HOU, X. and BERGSTRÖM, J. 1995. Cambrian lobopodians–ancestors of extant onychophorans? Zoological Journal of the Linnean Society, 114, 3–19.
  • HOWARD, R. J., HOU, X., EDGECOMBE, G. D., SALGE, T., SHI, X. and MA, X. 2020. A tube-dwelling early Cambrian lobopodian. Current Biology, 30, 1529-1536.e2.
  • RAMSKÖLD, L. 1992. The second leg row of Hallucigenia discovered. Lethaia, 25, 221–224.
  • RAMSKÖLD, L. and HOU, X. G. 1991. New early Cambrian animal and onychophoran affinities of enigmatic metazoans. Nature, 351, 225–228.
  • SMITH, M. R. and ORTEGA-HERNANDEZ, J. 2014. Hallucigenia’s onychophoran-like claws and the case for Tactopoda. Nature, 514, 363–366.
  • SMITH, M. R. and CARON, J.-B. 2015. Hallucigenia’s head and the pharyngeal armature of early ecdysozoans. Nature, 523, 75–78.
  • STEINER, M., HU, S. X., LIU, J. and KEUPP, H. 2012. A new species of Hallucigenia from the Cambrian Stage 4 Wulongqing Formation of Yunnan (South China) and the structure of sclerites in lobopodians. Bulletin of Geosciences, 87, 107–124.
  • WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5), 109–145.
  • ———. 1931. Addenda to descriptions of Burgess Shale fossils. Smithsonian Miscellaneous Collections, 85(3), 1–46.
  • YANG, J., ORTEGA-HERNANDEZ, J., GERBER, S., BUTTERFIELD, N. J., HOU, J., LAN, T. and ZHANG, X. 2015. A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora. Proceedings of the National Academy of Sciences of the United States of America, 112, 8678–8683.
Other Links:

http://gsc.nrcan.gc.ca/paleochron/09_e.php

http://paleobiology.si.edu/burgess/hallucigenia.html

http://evolution.berkeley.edu/evolibrary/article/_0_0/cambrian_13



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Pirania muricata

3D animation of Pirania muricata and other sponges (Choia ridleyi, Diagoniella cyathiformis, Eiffelia globosa, Hazelia conferta, Vauxia bellula, and Wapkia elongata) and Chancelloria eros a sponge-like form covered of star-shaped spines.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Demospongea (Order: Monaxonida)
Species name: Pirania muricata
Remarks:

Pirania is considered a primitive demosponge (Rigby, 1986). Demosponges, the same group that are harvested as bath sponges, represent the largest class of sponges today.

Described by: Walcott
Description date: 1920
Etymology:

Pirania – from Mount Saint Piran (2,649 m), situated in the Bow River Valley in Banff National Park, Alberta. Samuel Allen named Mount St. Piran after the Patron Saint of Cornwall in 1894.

muricata – from the Latin muricatus, “pointed, or full of sharp points.” The name refers to the large pointed spicules extending out from the wall of the sponge.

Type Specimens: Lectotype –USNM66495 (erroneously referred as 66496 in Rigby, 1986), in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none

Other deposits: Pirania auraeum Botting, 2007 from the Lower Ordovician of Morocco (Botting, 2007); Pirania llanfawrensis Botting, 2004 from the Upper Ordovician of England (Botting, 2004).

Age & Localities:

Age:
Middle Cambrian, Bathyuriscus-Elrathina Zone (approximately 505 million years ago).
Principal localities:

The Walcott Quarry on Fossil Ridge. The Trilobite Beds and Tulip Beds (S7) on Mount Stephen and several smaller sites on Mount Field, Mount Stephen and Mount Odaray.

History of Research:

Brief history of research:

Pirania was first described by Walcott (1920). Rigby (1986) redescribed this sponge and concluded that the skeleton is composed of hexagonally arranged canals, large pointed spicules and tufts of small spicules. This sponge was also reviewed by Rigby and Collins based on new material collected by the Royal Ontario Museum (2004).

Description:

Morphology:

Pirania is a thick-walled cylindrical sponge that can have up to four branches. The skeleton of the sponge is composed of tufts of small spicules and has very distinctive long pointed spicules that emerge from the external wall. Long canals perforate the wall of the sponge to allow water flow through it. Branching occurs close to the base of the sponge.

Abundance:

Pirania is common in most Burgess Shale sites but comprises only 0.38% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
30 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

Pirania would have lived attached to the sea floor. Particles of organic matter were extracted from the water as they passed through canals in the sponge’s wall. The brachiopods Nisusia and Micromitra a range of other sponges and even juvenile chancelloriids are often found attached to the long spicules of this sponge, possibly to avoid higher turbidity levels near the seafloor.

References:

BOTTING, J. P. 2004. An exceptional Caradoc sponge fauna from the Llanfawr Quarries, Central Wales and phylogenetic implications. Journal of Systematic Paleontology, 2: 31-63.

BOTTING, J. P. 2007. ‘Cambrian’ demosponges in the Ordovician of Morocco: insights into the early evolutionary history of sponges. Geobios, 40: 737-748.

CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

RIGBY, J. K. 1986. Sponges of the Burgess shale (Middle Cambrian), British Columbia. Palaeontographica canadiana, 2: 105 p.

RIGBY, J. K. AND D. COLLINS. 2004. Sponges of the Middle Cambrian Burgess Shale and Stephen Formations, British Columbia. Royal Ontario Museum Contributions in Science (1): 155 p.

WALCOTT, C. D. 1920. Middle Cambrian Spongiae. Cambrian Geology and Paleontology IV. Smithsonian Miscellaneous Collections, 67(6): 261-365.

Other Links:

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Pikaia gracilens

3D animation of Pikaia gracilens.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Unranked clade (stem group chordates)
Species name: Pikaia gracilens
Remarks:

Pikaia is considered to represent a primitive chordate (Conway Morris, 1979; Conway Morris et al., 1982) possibly close to craniates (Janvier, 1998); a stem-chordate (Smith et al., 2001); or a cephalochordate (Shu et al., 1999). Its exact position within the chordates is still uncertain and this animal awaits a full redescription.

Described by: Walcott
Description date: 1911
Etymology:

Pikaia – from the pika, a small alpine mammal and cousin of the rabbits. Pikas live in the Rocky Mountains, including near the Burgess Shale.

gracilens – from the Latin gracilens, “thin, simple,” in reference to the shape of the body.

Type Specimens: Syntypes –USNM57628b, 57629 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: none.

Age & Localities:

Age:
Middle Cambrian, Bathyuriscus-Elrathina Zone (approximately 505 million years ago).
Principal localities:

The Walcott Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Pikaia was first described by Walcott based on a couple of specimens in a 1911 monograph dealing with various Burgess Shale worms. Two additional specimens were figured in a posthumous publication (Walcott, 1931). Walcott placed Pikaia in a now defunct group called the Gephyrea with other vermiform fossils such as Banffia, Ottoia and Oesia. Pikaia was later considered to be a primitive chordate (Conway Morris, 1979; Conway Morris et al., 1982), an interpretation which has since been followed to some degree in most discussions about early chordate evolution (e.g., Janvier, 1998). Pikaia played a major part in Gould’s interpretations of the Burgess Shale fossils in Wonderful Life (Gould, 1989; see also Briggs and Fortey, 2005). A full redescription of this animal is currently under way (Conway Morris and Caron, in prep.).

Description:

Morphology:

Pikaia resembles Metaspriggina in outline, another chordate animal from the Burgess Shale, with an elongate body and a small anterior region bearing the head. The body is laterally flattened and there is evidence of a ventral fin towards the posterior. Numerous V-shaped or ziz-zag segments interpreted as myomeres or muscle bands are visible in all specimens. A narrow dorsal structure which runs down the length of the organism might represent a notochord, but this interpretation remains to be confirmed. The head bears two equal lobes and a pair of short and slender tentacle-like structures. There is no evidence of eyes. Just behind the head, on the ventral side of the body, there is a series of up to twelve pairs of small, short, pointed structures on either side of the midline. These are thought to be related to gill openings. The gut is narrow and the anus is terminal.

Abundance:

Pikaia is relatively rare, known from more than 60 specimens, all from the Walcott Quarry where it represents 0.03% of the specimens counted in the community (Caron and Jackson, 2008).

Maximum Size:
55 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

The eel-like morphology and musculature of the animal suggest that it was likely free-swimming, although it probably spent time on the sea floor. The tentacles may have had a sensory function, and the presence of mud in its gut suggests that Pikaia was potentially a deposit feeder.

References:

BRIGGS, D. E. G. AND R. A. FORTEY. 2005. Wonderful strife: Systematics, stem groups, and the phylogenetic signal of the Cambrian radiation. Paleobiology, 31(SUPPL.2 ): 94-112.

CONWAY MORRIS, S. 1979. The Burgess Shale (Middle Cambrian) fauna. Annual Review of Ecology and Systematics, 10(1): 327-349.

CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

CONWAY MORRIS, S. H. B. WHITTINGTON, D. E. G. BRIGGS, C. P. HUGHES AND D. L. BRUTON. 1982. Atlas of the Burgess Shale. Palaeontological Association, 31 p. + 23 pl.

GOULD, S. J. 1989. Wonderful Life. The Burgess Shale and the Nature of History. Norton, New York, 347 p.

JANVIER, P. 1998. Les vertébrés avant le Silurien. GeoBios, 30: 931-950.

SHU, D.-G,. H. L. LUO, S. CONWAY MORRIS, X. L. ZHANG, S. X. HU, L. CHEN, J. HAN, M. ZHU, Y. LI AND L. Z. CHEN. 1999. Lower Cambrian vertebrates from south China. Nature, 402(4 November 1999): 42-46.

SMITH, M. P., I. J. SANSOM AND K. D. COCHRANE. 2001. The Cambrian origin of vertebrates, p. 67-84. In P. E. Ahlberg (ed.), Major Events in Early Vertebrate Evolution: Palaeontology, Phylogeny, Genetics and Development. Taylor and Francis, London.

WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-145.

WALCOTT, C. 1931. Addenda to descriptions of Burgess Shale fossils. Smithsonian Miscellaneous Collections, 85(3): 1-46.

Other Links:

http://paleobiology.si.edu/burgess/pikaia.html



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Eldonia ludwigi

3D animation of Eldonia ludwigi.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: 3D Animation
Phylum: 3D Animation
Higher Taxonomic assignment: Unranked clade Cambroernida (stem group ambulacrarians)
Species name: Eldonia ludwigi
Remarks:

Eldonia, together with other discoidal or pedunculate fossils such as Herpetogaster, probably belongs in the stem group to a clade known as the Ambulacraria, represented by both echinoderms and hemichordates (Caron et al., 2010).

Described by: Walcott
Description date: 1911
Etymology:

Eldonia – from Eldon, a train stop on the Canadian Pacific Railway 30 km east of Field. Eldon is named after a town in County Durham, England, and means “Aelle’s hill.”

ludwigi – after Hubert Ludwig, a German echinoderm expert who described many fossil holothurians.

Type Specimens: Lectotype –USNM57540 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: Stellostomites eumorphus (Sun and Hou, 1987), from the Lower Cambrian Chengjiang fauna, was redescribed as Eldonia eumorpha (Chen et al., 1995). However, S. eumorphus is retained in the literature as the only valid species (Zhu et al. 2002); E. berbera was described from the Upper Ordovician of Morocco (Alessandrello and Bracchi, 2003). If confirmed it would be the youngest stratigraphic occurrence for the genus.

Age & Localities:

Age:
Middle Cambrian, Bathyuriscus-Elrathina Zone to Bolaspidella Zone (approximately 505 million years ago).
Principal localities:

Burgess Shale and vicinity: Walcott and Raymond Quarries on Fossil Ridge.

Other deposits: Middle Cambrian Spence Shale and Marjum Formation in Utah (Conway Morris and Robison, 1988).

History of Research:

Brief history of research:

Described by Walcott in 1911, Eldonia was originally interpreted as a holothurian (sea cucumber within the echinoderms), a view that was accepted by some eminent experts at the time (Clark A.H., 1913) and upheld by later re-examination of the material (Durham, 1974). However, this interpretation has always had detractors (Clark H.L., 1912; Dzik, 1991, 1997; Madsen, 1956, 1957, 1962; Paul and Smith, 1984), and the lack of key echinoderm features prohibits a close relationship with that group (Conway Morris, 1993; see also Zhu et al., 2002). Despite their resemblance to jellyfish (scyphozoans) there is a wide consensus that eldoniids do not share any affinities with cnidarians. A connection to “lophophorates” (e.g., brachiopods, phoronids) has been argued in more detail (Chen et al., 1995, Dzik, 1997), but this status remains rather problematic. The description of Eldonia’s close relative Herpetogaster provides a possible link to the Ambulacraria, a group that contains the echinoderms and hemichordates (Caron and Conway Morris, 2010).

Fragments of the reflective gut have been extracted by acid maceration and analyzed for taphonomic studies (Butterfield, 1990).

Description:

Morphology:

Eldonia has a discoidal body with both anus and mouth opening ventrally. Fine rays radiate from a central point within the disc. The gut coils clockwise (viewed from the dorsal surface) around the centre of the organism and is clearly separated into a pharynx, stomach (the darker area), and narrow intestine. There is a pair of relatively stout tentacles around the mouth which probably were used for feeding.

Abundance:

Walcott collected hundreds of specimens of Eldonia in a single fossil layer within the Phyllopod Bed that he called the Great Eldonia Layer. Additional specimens have since been collected from the Walcott Quarry, where they comprise 0.4% of the community (Caron and Jackson, 2008).

Maximum Size:
150 mm

Ecology:

Life habits: 3D Animation
Feeding strategies: 3D Animation
Ecological Interpretations:

Eldonia has conventionally been interpreted as a free-floating filter-feeder. However, based on its morphology, preservational patterns, and its similarity with Herpetogaster, a benthic lifestyle has also been proposed, with its tentacles either collecting food from the water, or sweeping the sea floor for particles of detritus (Caron and Conway Morris, 2010). It is unclear whether the animal could move at least occasionally or was permanently stationary (sessile).

References:

ALESSANDRELLO, A. AND G. BRACCHI. 2003. Eldonia berbera n. sp. a new species of the enigmatic genus Eldonia Walcott, 1911 from the Rawtheyan (Upper Ordovician) of Anti-Atlas (Erfoud, Tafilalt, Morocco). Atti della Società italiana di scienze naturali e del Museo civico di storia naturale in Milano, 144(2): 337-358.

BUTTERFIELD, N. J. 1990. Organic preservation of non-mineralizing organisms and the taphonomy of the Burgess Shale. Paleobiology, 16(3): 272-286.

CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

CARON, J.-B., S. CONWAY MORRIS AND D. SHU. 2010. Tentaculate fossils from the Cambrian of Canada (British Columbia) and China (Yunnan) interpreted as primitive deuterostomes. PLoS ONE, 5(3): e9586.

CHEN, J.-Y., M.-Y. ZHU AND G.-Q. ZHOU. 1995. The early Cambrian medusiform metazoan Eldonia from the Chengjiang Lagerstätte. Acta Palaeontologica Polonica, 40: 213-244.

CLARK, H. L. 1912. Fossil holothurians. Science, 35(894): 274-278.

CLARK, A. H. 1913. Cambrian holothurians. American Naturalist, 48: 488-507.

CONWAY MORRIS, S. AND R. A. ROBISON. 1988. More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia. The University of Kansas Paleontological Contributions, 122: 23-84.

CONWAY MORRIS, S. 1993. The fossil record and the early evolution of the Metazoa. Nature, 361(6409): 219-225.

DURHAM, J. W. 1974. Systematic Position of Eldonia ludwigi Walcott. Journal of Paleontology, 48(4): 751-755.

DZIK, J. 1991. Is fossil evidence consistent with traditional views of the early metazoan phylogeny?, p. 47-56. In A. M. Simonetta and S. Conway Morris (eds.), The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Cambridge.

DZIK, J. Y., L. ZHAO AND M. Y. ZHU. 1997. Mode of life of the Middle Cambrian eldonioid lophophorate Rotadiscus. Palaeontology, 40(2):385-396.

MADSEN, F. J. 1956. Eldonia, a Cambrian siphonophore-formerly interpreted as a holoturian[sic]. Videnskabelige meddelelser fra Dansk naturhistorisk forening i Københaven, 118: 7-14.

MADSEN, F. J. 1957. On Walcott’s supposed Cambrian holothurians. Journal of Paleontology, 31(1): 281-282.

MADSEN, F. J. 1962. The systematic position of the Middle Cambrian fossil Eldonia. Meddelelser fra Dansk Geologisk Førening, 15: 87-89.

PAUL, C. R. C. AND A. B. SMITH. 1984. The early radiation and phylogeny of echinoderms. Biological Reviews, 59(4): 443-481.

WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian holothurians and medusae. Smithsonian Miscellaneous Collections, 57(3): 41-68.

ZHU, M. Y., Y. L. ZHAO AND J. Y. CHEN. 2002. Revision of the Cambrian discoidal animals Stellostomites eumorphus and Pararotadiscus guizhouensis from South China. Geobios, 35(2): 165-185.

Other Links:

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