The Burgess Shale

Fossil Ridge: Raymond Quarry

Eldonia ludwigi

3D animation of Eldonia ludwigi.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
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: Raymond Quarry
Feeding strategies: Raymond Quarry
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:

None

Ehmaniella burgessensis

Ehmaniella burgessensis (ROM 60759) – Part and counterpart. Complete specimen. Specimen length = 6 mm. Specimen dry – direct light (left) and coated with ammonium chloride sublimate to show details (middle, right). Walcott Quarry

© Royal Ontario Museum. Photo: Jean-Bernard Caron

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Trilobita (Order: Ptychopariida)
Species name: Ehmaniella burgessensis
Remarks:

Trilobites are extinct euarthropods, probably stem lineage representatives of the Mandibulata, which includes crustaceans, myriapods, and hexapods (Scholtz and Edgecombe, 2006).

Described by: Rasetti
Description date: 1951
Etymology:

Ehmaniella – modification of Ehmania, a trilobite genus name coined in 1935 by C. E. Resser to honour Philip Ehman (Montana) for his geological assistance.

burgessensis – from the Burgess Shale.

Type Specimens: Holotype (E. burgessensis) – USNM116245; Holotype (E. waptaensis) – USNM116243 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: Ehmaniella waptaensis Rasetti, 1951.

Other deposits: other species have been reported from elsewhere in the Cambrian of North America.

Age & Localities:

Age:
Middle Cambrian, 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 smaller localities on Mount Odaray.

History of Research:

Brief history of research:

Walcott illustrated two Burgess Shale trilobite specimens in establishing Ptychoparia permulta in 1918. Resser (1937) saw that the two individuals belonged in different species, but erroneously used Walcott’s clearly designated primary type of permulta to found the new combination Elrathia dubia. Rasetti (1951) declared Resser’s dubia invalid, left the original type of permulta in Elrathia, and employed Walcott’s other specimen as a paratype of a new species (burgessesnsis), which he assigned to Resser’s 1937 genus Ehmaniella. Ehmaniella waptaensis, also described by Rasetti in 1951, is nearly indistinguishable.

Description:

Morphology:

Hard parts: adult dorsal exoskeletons may reach 2.8 cm long. The semicircular cephalon is about one-third the length of the dorsal shield, bordered by a well-defined rounded rim; wide free cheeks often show anastomosing ridges and carry short, sharp genal spines. Strong transverse eye ridges extend to relatively large eyes, which are located at or behind cephalic mid-length. The bluntly rounded glabella tapers evenly forward and bears three pairs of shallow lateral furrows; the pre-glabellar field is short. A thorax of thirteen parallel-sided segments has a barrel-shaped outline and a rather broad axial lobe. The short, wide, rounded triangular pygidium usually shows 4 or 5 axial rings with corresponding pleurae. The surface of the exoskeleton is variably granulate.

Unmineralized anatomy: rare specimens of Ehmaniella from the Walcott Quarry and above on Fossil Ridge preserve a pair of slender uniramous antennae (Walcott, 1918; Rudkin 1989). These are sometimes associated with a dark stain adjacent to the exoskeleton, presumably representing fluidized decay products.

Abundance:

Relatively common on Fossil Ridge and locally abundant in the Walcott Quarry (fourth most common trilobite with about 400 specimens observed, only 13 of which are E. waptaensis, Caron and Jackson, 2008).

Maximum Size:
28 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

Like similar-looking ptychoparioid trilobites, Ehmaniella may be interpreted as a fully mobile, epibenthic deposit (particle) feeder.

References:

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

RASETTI, F. 1951. Middle Cambrian stratigraphy and faunas of the Canadian Rocky Mountains. Smithsonian Miscellaneous Collections, 116 (5): 277 p.

RESSER, C. E. 1935. Nomenclature of some Cambrian trilobites. Smithsonian Miscellaneous Collections, 95(22): 29 p.

RESSER, C. E. 1937. Third contribution to nomenclature of Cambrian trilobites. Smithsonian Miscellaneous Collections, 93(5): 46 p.

RUDKIN, D. M. 1989. Trilobites with appendages from the Middle Cambrian Stephen Formation of British Columbia. 28th International Geological Congress, Washington, D.C. July 9-19, 1989. Abstracts: 2-729.

SCHOLTZ, G. AND G. D. EDGECOMBE. 2006. The evolution of arthropod heads: reconciling morphological, developmental and palaeontological evidence. Development Genes and Evolution, 216: 395-415.

WALCOTT, C. 1918. Cambrian Geology and Paleontology IV. Appendages of trilobites. Smithsonian Miscellaneous Collections, 67(4): 115-216.

Other Links:

http://www.trilobites.info/ordptychopariida.htm

Diraphora bellicostata

3D animation of Diraphora bellicostata and other brachiopods (Acrothyra gregaria, Micromitra burgessensis, Nisusia burgessensis, and Paterina zenobia).

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Rhynchonellata (Order: Orthida)
Species name: Diraphora bellicostata
Remarks:

Diraphora belongs to the Family Bohemiellidae.

Described by: Walcott
Description date: 1924
Etymology:

Diraphora – from the Greek deiras, “ridge,” and phoras, “bearing.”

bellicostata – from the Latin bellus, “beautiful,” and costatus, “ribbed.”

Type Specimens: Syntypes –USNM69731-69737 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none to date. The Burgess Shale brachiopods in particular from the Trilobite Beds on Mount Stephen need to be re-examined (see also Brief history of research).

Other deposits: Several species are known in North America and Australia.

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:

Originally assigned to Eoorthis by Walcott (1924), this species was subsequently reassigned by Bell as the type species of a new genus, Diraphora (Bell, 1941). Diraphora bellicostata has not been studied since its original description by Walcott in 1924. Walcott’s description is cursory, inadequately diagnosing the specimen, and no types were designated. The species needs to be redescribed.

Description:

Morphology:

Diraphora bellicostata possesses sharp ornamental lines (costae) radiating on its surface from the hinge. The shells would have been articulated with short and small teeth, like in Nisusia, a comparable form from the Burgess Shale. No preserved soft parts are known and the shell was originally mineralized.

Abundance:

Diraphora bellicostata is known from several hundred specimens in the Walcott Quarry and is the most abundant of all brachiopods but still represents a relatively small fraction of the entire fauna (<1.3%) (Caron and Jackson, 2008).

Maximum Size:
10 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

It is likely that Diraphora had a short, stout pedicle from which it was attached to the substrate. Some specimens are attached to spicules of sponges in particular of Pirania. Other organisms (for example Mackenzia) attached themselves on isolated valves of Diraphora (representing dead individuals), which they used as anchors. Extraction of food particles from the water would have been possible thanks to a filter-feeding apparatus (located between the shells) called a lophophore.

References:

BELL, C. W. 1941. Cambrian Brachiopoda from Montana. Journal of Paleontology, 15: 193-255.

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

WALCOTT, C. D. 1924. Cambrian and Ozarkian Brachiopoda. Cambrian Geology and Paleontology IV. Smithsonian Miscellaneous Collections, 67: 477-554.

Other Links:

None

Dinomischus isolatus

Reconstruction of Dinomischus isolatus.

© Marianne Collins

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Non applicable
Species name: Dinomischus isolatus
Remarks:

Although it has been suggested that Dinomischus may be related to the ectoprocts (Conway Morris, 1977), its unusual morphology has not yet been conclusively related to a known phylum and as such its affinities remain unclear.

Described by: Conway Morris
Description date: 1977
Etymology:

Dinomischus – from the Greek dinos, “goblet,”, and michos, “stalk or stem.” The name refers to the wine glass-shape of the animal.

isolatus – from the Latin insula, “island.” The name refers to the non-gregarious life habit of this animal.

Type Specimens: Holotype –USNM198735 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: D. venutus Chen, Hou and Lu, 1989 from the Lower Cambrian Chengjiang fauna.

Age & Localities:

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

Burgess Shale and vicinity: Walcott Quarry, Raymond Quarry, Tulip Beds (S7)

Other deposits: A single specimen of D. isolatus was also reported from the Middle Cambrian Kaili Formation (Peng et al., 2006).

History of Research:

Brief history of research:

D. isolatus was among the original fossils collected by Walcott, although it was not formally described until 1977 by Conway Morris. The original description was based on three specimens. A second species was added by Chen et al. (1989) based on material from the Chengjiang in China. Further specimens have been collected by the Royal Ontario Museum from sites on both Fossil Ridge and Mount Stephen.

Description:

Morphology:

Dinomischus consists of a cup-shaped calyx supported by a long stem that terminates in a bulbous swelling. A circle of 20 stiff bracts up to 4.5 mm in length surround the upper margin of the calyx. These point upward and project beyond the level of the anus and the mouth and are interpreted as part of a filter feeding apparatus. Reflective material in the central part of the calyx has been interpreted as a U-shaped gut, with a large sac-like stomach positioned centrally and a mouth and anus on the upper surface. The stem appears to be a rigid structure and the bulbous termination is interpreted as an attachment structure.

Abundance:

Dinomischus is very rare. Only three specimens were originally described from the Burgess Shale. A few additional specimens are known in the Burgess Shale collections of the Royal Ontario Museum.

Maximum Size:
28 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

Dinomischus was a stalked filter feeder that lived anchored to the sea floor. Its ring of bracts would have captured food particles from passing water and moved them to the mouth.

References:

CONWAY MORRIS, S. 1977. A new entoproct-like organism from the Burgess Shale of British Columbia. Palaeontology, 20(4): 833-845.

CHEN, J. HOU, X. AND H. LU. 1989. Early Cambrian hock glass-like rare sea animal Dinomischus (Entoprocta) and its ecological features. Acta Palaeontologica Sinica., 28 (1): 58-71.

PENG, J., Y. L. ZHAO AND J. P. LIN. 2006. Dinomischus from the Middle Cambrian Kaili Biota, Guizhou, China. Acta Geologica Sinica-English Edition, 80: 498-501.

Other Links:

None

Liangshanella burgessensis

3D animation of Liangshanella burgessensis.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Unranked clade (Order: Bradoriida, stem group arthropods)
Species name: Liangshanella burgessensis
Remarks:

Liangshanella is a bradoriid belonging to the family Svealutidae (Siveter and Williams, 1997). The bradoriids were traditionally compared to other bivalved arthropods, such as Recent ostracods (e.g. Sylvester-Bradley, 1961) and Cambrian phosphatocopids (e.g. Maas et al., 2003). However, they are thought to be in the stem-lineage or in a sister group position relative to the Crustaceans (e.g. Hou et al., 1996; Shu et al., 1999; Hou et al., 2010).

Described by: Siveter and Williams
Description date: 1997
Etymology:

Liangshanella – from Liangshan, a region in South Shaanxi, China.

burgessensis – from the Burgess Shale. The name is derived from Mount Burgess (2,599 m), a mountain peak in Yoho National Park. Mount Burgess was named in 1886 by Otto Klotz, the Dominion topographical surveyor, after Alexander Burgess, a former Deputy Minister of the Department of the Interior.

Type Specimens: Holotype –USNM272083 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: L. circumbolina from the Flinders Ranges in South Australia; L. liangshanensis, L. rotundata, L. orbicularis, L. yunnanensis and L. baensis from southern China; L. lubrica from the Tongying Formation in Hubei, China; L. sayutinae from the Trans-Baikal area in the Russian Far-East and Greenland; L. birkenmajeri from Antarctica. See references in Siveter and Williams (1997).

Age & Localities:

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

The Walcott and Raymond Quarries on Fossil Ridge.

History of Research:

Brief history of research:

Liangshanella liangshanensis is the type species of this genus and was first described by Huo (1956) from Lower Cambrian rocks of south China. Further species have since been described in China (Zhang, 1974; Li, 1975; Qian and Zhang, 1983; Zhang, 2007), Russia and Greenland (Melnikova, 1988), Australia (Topper et al., in press) and Antarctica (Wrona, 2009). Liangshanella burgessensis from the Burgess Shale was described by Siveter and Williams (1997), and the genus has been included in studies on the biogeography, evolution and affinity of the bradoriids (e.g. Shu and Chen, 1994; Williams et al., 2007).

Description:

Morphology:

Like all bradoriids, Liangshanella burgessensis has a small bivalved carapace with a straight dorsal hinge held together by a band of cuticle. The carapaces range in length from 0.66 mm – 4.25 mm and were soft and unmineralized. The bivalved carapace of L. burgessensis is sub-circular, with the anterior end being slightly narrower than the posterior end. There is a marginal ridge along the lateral surface of the valves. A centrally situated, sub-circular muscle scar composed of numerous small pits can be seen inside the valve. No evidence of soft parts has been found.

Abundance:

Liangshanella burgessensis is known from thousands of specimens and is the most common taxon in the Walcott Quarry (11.8% of the community, Caron and Jackson, 2008).

Maximum Size:
10 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

Liangshanella was likely epibenthic, living on and within the first few metres of the soft muddy seafloor. Like other bradoriids, Liangshanella was probably a deposit feeder, and may have even been scavenging or predating on microscopic non-mineralized animals (Williams et al., 2007). Most specimens of Liangshanella found are empty carapaces, being left over from when the animal moulted its exoskeleton. Bradoriids are extremely common in Cambrian rocks, suggesting they played important roles in recycling nutrients in the seabed (Shu et al., 1999). They were also important food sources for larger animals, as indicated by their common presence in coprolites (e.g. Vannier and Chen, 2005).

References:

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

HOU, X., D. J. SIVETER, M. WILLIAMS, D. WALOSSEK AND J. BERGSTRÖM. 1996. Preserved appendages in the arthropod Kunmingella from the early Cambrian of China: its bearing on the systematic position of the Bradoriida and the fossil record of the Ostracoda. Philosophical Transactions of the Royal Society, B351: 1131-1145.

HOU, X., M. WILLIAMS, D.J. SIVETER, D.J. SIVETER, R.J. ALDRIDGE AND R.S. SANSOM. 2010. Soft-part anatomy of the Early Cambrian bivalve arthropods Kunyangella and Kunmingella: significance for the phylogenetic relationships of Bradoriida. Proceedings of the Royal Society, B277: 1835-1841.

HUO, S. 1956. Brief notes on lower Cambrian Archaeostraca from Shensi and Yunnan. Acta Palaeontologica Sinica, 4: 425-445.

LI, Y. 1975. Cambrian Ostracoda and other new descriptions from Sichuan, Yunnan and Shaanxi. Professional Papers of Stratigraphy and Palaeontology, 2: 37-72.

MAAS, A., D. WALOSZEK AND K.J. MÜLLER. 2003. Morphology, ontogeny and phylogeny of the Phosphatocopina (Crustacea) from the Upper Cambrian “Orsten” of Sweden. Fossils and Strata, 49: 1-238.

MELNIKOVA, L. M. 1988. Nekotoryye bradoriidy (Crustacea) iz botomskogo yarusa vostochnogo Zabaykal’ya. Paleontologicheskiy Zhurnal, 1: 114-117.

QIAN, Y. AND S. ZHANG. 1983. Small shelly fossils from the Xihaoping Member of the Tongying Formation in Fangxian County of Hubei Province and their stratigraphical significance. Acta Palaeontologica Sinica, 22: 82-94

SHU, D. AND L. CHEN. 1994. Cambrian palaeobiogeography of Bradoriida. Journal of Southeast Asian Earth Sciences, 9: 289-299.

SHU, D., J. VANNIER, H. LUO, L. CHEN, X. ZHANG AND S. HU. 1999. Anatomy and lifestyle of Kunmingella (Arthropoda, Bradoriida) from the Chengjiang fossil Lagerstätte (Lower Cambrian, Southwest China). Lethaia, 35: 279-298.

SIVETER, D.J. AND M. WILLIAMS. 1997. Cambrian Bradoriid and Phosphatocopid Arthropods of North America. Special Papers in Palaeontology, 57: 1-69.

SYLVESTER-BRADLEY, P. C. 1961. Archaeocopida, p. Q100-103. In R. C. Moore, and C. W. Pitrat (Eds.), Treatise on Invertebrate Paleontology Part Q, Arthropoda 3, Crustacea, Ostracoda. Geological Society of America and University of Kansas Press, Boulder, Colorado and Lawrence, Kansas.

Other Links:

None

Pagetia bootes

Pagetia bootes (ROM 60756). Complete individual. Specimen length = 4.5 mm. Specimen dry – direct light (left) and coated with ammonium chloride sublimate to show details (right). Walcott Quarry.

© ROYAL ONTARIO MUSEUM. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Trilobita (Order: Agnostida)
Species name: Pagetia bootes
Remarks:

Trilobites are extinct euarthropods, probably stem lineage representatives of the Mandibulata, which includes crustaceans, myriapods, and hexapods (Scholtz and Edgecombe, 2006).

Described by: Walcott
Description date: 1916
Etymology:

Pagetia – unspecified, likely from Paget Peak (2565 m) in Yoho National Park, named for the Very Reverend Dean Paget, founding member of the Alpine Club of Canada, who, in 1904, made the first recorded ascent.

bootes – unspecified, probably from the Greek Boötes meaning herdsman or ploughman; name of a northern constellation.

Type Specimens: Syntypes (P. bootes ) – USNM62855-62861; Holotype (P. walcotti) – USNM146310 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: P. walcotti Rasetti, 1966.

Other deposits: many species worldwide, in Lower and Middle Cambrian rocks.

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 on Mount Stephen.

History of Research:

Brief history of research:

Walcott (1916) published only a very brief description when he first named and illustrated this species. A full account finally appeared in Rasetti (1966), along with that of a new Burgess Shale species, P. walcotti.

Description:

Morphology:

Hard parts: adult dorsal exoskeletons reach about 10 mm in length (including the pygidial spine). The cephalon is semicircular, with a narrow flattened rim crossed by radiating furrows around the front margin. The glabella is narrow and anteriorly pointed with weak lateral constrictions; a delicate spine (usually broken off and not seen) extends up and back from the occipital ring. Tiny eyes are located well out on short, narrow cheeks bounded by proparian facial sutures. There are two thoracic segments. The pygidium is about the same size and outline shape as the cephalon, with a narrow axis of five rings and a terminal piece bearing a slender rearward projecting spine (often broken off). Faint pleural furrows may be visible on the pygidium.

P. walcotti is very similar, but the dorsal exoskeleton bears fine granules.

Unmineralized anatomy: not known.

Abundance:

P. bootes is very common in the Walcott Quarry. It is the third most common trilobite with at least 1000 specimens observed (Caron and Jackson, 2008), prompting Rasetti (1951) to define the “Pagetia bootes faunule” as the conventional shelly fossil assemblage associated with the exceptionally preserved soft-bodied biota. The co-occurring P. walcotti is very rare.

Maximum Size:
10 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

Adult eodiscine trilobites were members of the mobile benthic epifauna, possibly, like their co-occuring agnostine cousins, micrograzers or deposit (particle) feeders, adapted to colder, deeper, offshore waters.

References:

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

RASETTI, F. 1951. Middle Cambrian stratigraphy and faunas of the Canadian Rocky Mountains. Smithsonian Miscellaneous Collections, 116(5):277 p.

RASETTI, F. 1966. Revision of the North American species of the Cambrian trilobite genus Pagetia. Journal of Paleontology, 40:502-511.

SCHOLTZ, G. AND G. D. EDGECOMBE. 2006. The evolution of arthropod heads: reconciling morphological, developmental and palaeontological evidence. Development Genes and Evolution, 216:395-415.

WALCOTT, C. D. 1916. Cambrian trilobites. Smithsonian Miscellaneous Collections, 64(5):301-456.

Other Links:

http://www.trilobites.info/ordagnostida.htm

2D reconstruction – see: http://www.trilobites.info/galagnostida.htm

Ottoia prolifica

3D animation of Ottoia prolifica.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Unranked clade (stem group priapulids)
Species name: Ottoia prolifica
Remarks:

Ottoia 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:

Ottoia – from Otto Pass (2,106 m), a few kilometres north-west of the Burgess Shale. The pass was named after Otto Klotz, an astronomer working for the Department of the Interior along the Canadian Pacific Railroad (read about Otto Klotz in the section “First Discoveries”)

prolifica – from the Latin proles, “offspring,” and ferax, “rich, fruitful,” in reference to the great number of specimens discovered.

Type Specimens: Lectotype –USNM57619 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none

Other deposits: Ottoia sp. from the Lower Cambrian Pioche Shale, Nevada (Lieberman, 2003).

Age & Localities:

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

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

Other deposits: The same species also occurs in the Middle Cambrian Spence Shale and Marjum Formations, Utah (Conway Morris and Robison, 1986).

History of Research:

Brief history of research:

Charles Walcott (1911) first described Ottoia as a tentative member of the now-dismantled grouping of worms called the Gephyrea, which included the priapulids as well as the sipunculans and echiurans. He emphasized a comparison with the sipunculans, leading some subsequent authors to consider it as a member of this phylum; others, however, suggested affinities with the parasitic acanthocephalans, or the priapulids (Banta and Rice, 1970). A re-analysis of the fossil material itself was not conducted until the 1970s, with work by Banta and Rice (1970) and Conway Morris (1977) supporting a relationship with the priapulids, which was later demonstrated to be at a stem-group level (Wills, 1998). Other work has focussed on the ecology of the Burgess Shale representatives (Bruton, 2001; Vannier, 2009; Vannier et al., 2010).

Description:

Morphology:

Ottoia is a priapulid worm with a tooth-lined mouthpart (proboscis) that could be inverted into the trunk; a short posterior tail extension could also be inverted. Ottoia reached 15 cm in length; the smallest specimens – presumably juveniles, but identical to adults – were just 1 cm long. The proboscis was adorned with 28 rows of hooks interspersed with a variety of spines. The worms are usually found curved into a U-shape, with their sediment-filled guts often visible running down the centre of the organism. The trunk was annulated, and bore two sets of four hooks arranged in a ring towards the rear end; these are the only traces of bilateral symmetry, with a radial symmetry superimposed on the organism. Ottoiaperiodically shed its cuticle to allow growth.

Abundance:

Ottoia is one of the more abundant Burgess Shale organisms, accounting for over 80% of the Walcott Quarry priapulids (Conway Morris, 1977) and over 1.3% of the entire Walcott Quarry community (Caron and Jackson, 2008); thousands of specimens are known.

Maximum Size:
150 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

Specimens of Haplophrentis carinatus preserved in the gut indicate that this hyolith was a staple of the Ottoia diet (Conway Morris, 1977). One fossil slab also shows nine specimens feeding on a recently-dead Sidneyia carcass (Bruton, 2001).

References:

BANTA, W. C. AND M. E. RICE. 1970. A restudy of the Middle Cambrian Burgess Shale fossil worm, Ottoia prolifica. International Symposium on the Biology of the Sipuncula and Echiura 2, Kotor: 79-90.

BRUTON, D. L. 2001. A death assemblage of priapulid worms from the Middle Cambrian Burgess Shale. Lethaia, 34(2):163-167.

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 J. S. PEEL. 2009. New Palaeoscolecidan Worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale. Acta Palaeontologica Polonica, 55(1): 141-156.

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

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.

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

Other Links:

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

Choia carteri

3D animation of Choia ridleyi and other sponges (Diagoniella cyathiformis, Eiffelia globosa, Hazelia conferta, 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: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Demospongea (Order: Monaxonida)
Species name: Choia carteri
Remarks:

Choia belongs to an early branch of siliceous sponge, the protomonaxonids at the base of the Demospongea (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:

Choia – derivation unknown, but probably from the Spanish word cholla referring to spiny cacti of the genus Opuntia which resembles the sponge Choia in shape and spiny elements.

carteri – in honor of H. J. Carter, a famous nineteenth century hexactinellid sponge specialist.

Type Specimens: Lectotypes –USNM66482 (C. carteri),USNM66487 (C. ridleyi), in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. (C. hindei, type and repository information unknown.)
Other species:

Burgess Shale and vicinity: C. ridleyi (Walcott, 1920) from the Walcott Quarry; C. hindei (Dawson, 1896) from the Raymond Quarry.

Other deposits: C. utahensis (Walcott, 1920) from the Middle Cambrian Wheeler and Marjum Formations in Utah (Rigby et al., 2010); C. xiaolantianensis from the Lower Cambrian Chengjiang biota (Hou et al., 1999), C. sp. from the same formation near Haikou, Yunnan Province (Luo et al., 1999); and C.? sriata from the Lower Cambrian Hetang Formation, Anhui Province (Xiao et al., 2005). Choia is also known from the Ordovician of Morocco (Botting, 2007).

Age & Localities:

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

Burgess Shale and vicinity: The Walcott and Raymond Quarries on Fossil Ridge. The Collins Quarry and Trilobite Beds on Mount Stephen.

Other deposits: C. hindei (Dawson, 1896) from the Ordovician of Quebec at Little Métis to the Middle Cambrian Burgess Shale; C. carteri, C. hindei from the Middle Cambrian Wheeler and Marjum Formations in Utah (Rigby et al., 2010).

History of Research:

Brief history of research:

Choia was first described by Walcott (1920) based on specimens from the Burgess Shale, Utah and Quebec. The material from the Burgess Shale was re-examined in detail by Rigby (1986) and Rigby and Collins (2004).

Description:

Morphology:

Choia carteri consists of a flattened elliptical disc, up to 2 cm in diameter (5 cm including the long spicules), formed by fine radiating spicules from which stronger and long spicules up to 30 mm in length radiate. Other species differ in size and spine coarseness. C. ridleyi is generally smaller (less than 1.5 cm) and C. hindei larger (up to 8 cm).

Abundance:

Choia is not common in the Walcott Quarry where it represents only 0.2% of the Walcott Quarry community (Caron and Jackson, 2008). Only one specimen of C. hindei is known from the Burgess Shale (Rigby and Collins, 2004).

Maximum Size:
50 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

The sponge was not anchored to the sediment, but simply sat unattached on the sea floor. The long spicules are interpreted to have maintained the sponge above the sediment-water interface. Particles of organic matter were extracted from the water as they passed through canals in the sponges wall.

References:

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.

DAWSON, J. W. 1896. Additional notes on fossil sponges and other organic remains from the Québec Group of Little Métis on the lower St. Lawrence; with notes on some of the specimens by Dr. G.J. Hinde. Transactions of the Royal Society of Canada, 2: 91-129.

HOU, X., J. BERGSTRÖM, H. WANG, X. FENG AND A. CHEN. 1999. The Chengjiang fauna exceptionally well-preserved animals from 530 million years ago. Yunnan Science and Technology Press, Kunming, 170 p.

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.

RIGBY, J. K. 1986. Sponges of the Burgess Shale (Middle Cambrian), British Columbia. Palaeontographica Canadiana, 2: 1-105.

RIGBY, J. K. AND D. COLLINS. 2004. Sponges of the Middle Cambrian Burgess Shale and Stephen Formations, British Columbia, 1, 155 p.

RIGBY, J. K., S. B. CHURCH AND N. K. ANDERSON. 2010. Middle Cambrian Sponges from the Drum Mountains and House Range in Western Utah. Journal of Paleontology, 84: 66-78.

WALCOTT, C. D. 1920. Middle Cambrian Spongiae. Smithsonian Miscellaneous Collections, 67(6): 261-364.

XIAO, S., J. HU, X. YUAN, R. L. PARSLEY AND R. CAO. 2005. Articulated sponges from the Lower Cambrian Hetang Formation in southern Anhui, South China: their age and implications for the early evolution of sponges. Palaeogeography, Palaeoclimatology, Palaeoecology, 220: 89-117.

Other Links:

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

Chancia palliseri

Chancia palliseri (USNM 116236a+b). Complete individual lacking free cheeks; a presumed moult. Specimen length = 37 mm. Walcott Quarry.

© Smithsonian Institution – National Museum of Natural History. Photo: Jean-Bernard Caron

 

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Trilobita (Order: Ptychopariida)
Species name: Chancia palliseri
Remarks:

Trilobites are extinct euarthropods, probably stem lineage representatives of the Mandibulata, which includes crustaceans, myriapods, and hexapods (Scholtz and Edgecombe, 2006).

Described by: Walcott
Description date: 1908
Etymology:

Chancia – unspecified.

palliseri – unspecified, but probably in reference to the Palliser Range of the Canadian Rockies (near Banff, AB), named by the Palliser Expedition (British North American Exploring Expedition, 1857-1860), led by John Palliser.

Type Specimens: Holotype –USNM94344 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
Other species:

Burgess Shale and vicinity: Chancia bigranulosa, C. latigena, C. odarayensis, and C. stenometopa have been described from rocks that are slightly older and slightly younger at nearby sites on Mount Stephen and Mount Odaray.

Other deposits: Other species of Chancia occur in Cambrian rocks of western North America.

Age & Localities:

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

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

History of Research:

Brief history of research:

Although this rare species was named and illustrated as Ptychoparia palliseri by Walcott in 1908 and reassigned to Elrathia by Resser in 1937, it wasn’t formally described until Rasetti placed it in the genus Chancia in 1951! Interestingly, Walcott had established Chancia in 1924 for a very similar species (C. ebdome) in the Spence Shale of Utah and Idaho.

Description:

Morphology:

Hard parts: adult dorsal exoskeletons may be up to 4 cm long. The semicircular cephalon occupies about 30% the length of the entire dorsal shield; it is bordered by a low narrow rim, and bears short thorn-like genal spines. Elevated transverse ridges extend across the broad fixed cheeks to small prominent eyes located forward of the mid-glabellar length. The convex and narrowly conical glabella has three pairs of lateral furrows angled sharply backwards. A markedly broad, flat preglabellar field is about one-quarter the length of the cephalon, measured on the midline. The thorax of 20 parallel-sided segments has a narrow axis; the wide pleural lobes are gently flexed ventrally two-thirds of their length from the axial furrow. The thorax narrows in a wide smooth curve backwards to a very short, broadly triangular pygidium with three poorly defined axial rings and a terminal piece.

Unmineralized anatomy: not known.

Abundance:

Relatively rare at the Mount Stephen Trilobite Beds, rarer still on Fossil Ridge.

Maximum Size:
40 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

Like other rather similar-looking Cambrian ptychoparioid trilobites, C. palliseri may have been adapted to very low oxygen levels, feeding on particulate matter on the sea bed.

References:

RASETTI, F. 1951. Middle Cambrian stratigraphy and faunas of the Canadian Rocky Mountains. Smithsonian Miscellaneous Collections, 116 (5): 277 p.

RESSER, C. E. 1937. Third contribution to nomenclature of Cambrian trilobites. Smithsonian Miscellaneous Collections, 95 (22): 29 p.

SCHOLTZ, G. AND G, D, EDGECOMBE. 2006. The evolution of arthropod heads: reconciling morphological, developmental and palaeontological evidence. Development Genes and Evolution, 216: 395-415.

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

WALCOTT, C. D. 1924. Cambrian and Lower Ozarkian trilobites. Smithsonian Miscellaneous Collections, 75(2): 53-60.

Other Links:

http://www.trilobites.info/ordptychopariida.htm

Chancelloria eros

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

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: Raymond Quarry
Phylum: Raymond Quarry
Higher Taxonomic assignment: Unranked clade Coeloscleritophora (Order: Chancelloriida)
Species name: Chancelloria eros
Remarks:

Two main hypotheses exist for the affinity of the chancelloriids: they may form a group with Halkieria and relatives, nested close to the base of the bilaterian tree (Bengtson, 2005), or they may simply represent a sponge-grade organism with an unusual mode of spicule formation (Sperling et al., 2007).

Described by: Walcott
Description date: 1920
Etymology:

Chancelloria – from the nearby Chancellor Peak (3,280 m), which was named to honour the Ontario Chancellor Sir John Boyd for his role in resolving an 1886 dispute between the Canadian Pacific Railway and the Canadian Government.

eros – unspecified; either from the Latin erosus, “gnawed off” or “consumed,” or the Greek erotikos, “pertaining to love.”

Type Specimens: Lectotype –USNM66524 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
Other species:

Burgess Shale and vicinity: none.

Other deposits: Walcott (1920) described C. drusilla, C. libo and C. yorkensis from Middle Cambrian deposits in the Conasauga shales of Georgia, the Conasauga shales of Alabama, and the York formation of Pennsylvania, respectively. Other workers have described C. maroccana Szduy, 1969 from the Lower Cambrian Campo Pisano Formation, Sardinia, Italy; C. pentacta Rigby, 1978, from the Middle Cambrian Wheeler Shale, Utah, USA (Rigby, 1978); C. sp., from the Cambrian Bright Angel Shale of Arizona (Elliott and Martin, 1987); C. cf. eros from the Early Cambrian (Branchian) Sekwi Formation, Mackenzie Mountains, Northwest Territories, Canada (Randell et al., 2005); C. sp., from the Elvinia Zone (Upper Cambrian) Collier Shale, Ouachita Mountains, west-central Arkansas (Hohensee and Stitt, 1989); C. sp. from King George Island, Antarctica (Wrona, 2004).

Age & Localities:

Age:
Cambrian Stage 2 (basal Botomian, upper Lower Cambrian) to uppermost Middle Cambrian, Bolaspidella Zone (approximately 525-505 million years ago).
Principal localities:

Burgess Shale and vicinity: Chancellorids are known from all Burgess Shale localities, in particular from the Walcott, Raymond and Collins Quarries on Fossil Ridge, as well as on Mount Stephen (Trilobite Beds, and Tulip Beds (S7)), Monarch Cirque and other smaller localities. Work is currently in progress to determine how many of these Chancelloria specimens in fact represent other genera, in particular Allonnia and Archiasterella (see below).

Other deposits: C. eros is globally distributed, and has been reported from the Middle Cambrian Wheeler Shale (and Marjum Formation), Utah, USA (Janussen et al., 2002); Lower Cambrian Comley Limestone, England (Reid, 1959); upper Lower to lower Middle Cambrian La Laja Formation, Argentina (Beresi and Rigby, 1994); Andrarum Limestone and the upper alum shale (Middle Cambrian) of Bornholm, Denmark (Berg-Madsen, 1985); Lower Cambrian of Nevada and California (Mason, 1938); the Lower Cambrian of Cape Breton Island (Landing, 1991); the Early Cambrian Todd River Dolomite, Amadeus Basin, central Australia (Laurie, 1986), the Çal Tepe Formation, Taurus Mountains, Turkey (Sarmiento et al., 2001); the Lower Cambrian Forteau Formation of western Newfoundland (Skovsted and Peel, 2007); the Lower Cambrian Hyolithes Limestone of Nuneaton, England (Brasier, 1984).

History of Research:

Brief history of research:

Walcott (1920) considered Chancelloria to represent a sponge, a position that was followed by the majority of subsequent workers. However its mode of sclerite formation is reputedly unlike anything known in modern sponges: the hollow sclerites are composed of multiple elements that are joined together (Bengtson and Missarzhevsky, 1981), with a structure similar to the sclerites of Halkieria (Porter, 2008). This detail convinced most that the chancelloriids could not belong to the sponges (Goryanski, 1973; Bengtson and Hou, 2001). However, some disagree, pointing out that the organic microstructure does have some similarity to the fibres of horny sponges (Butterfield and Nicholas, 1996), suggesting a position in the sponge total group (see also Sperling et al., 2007). The specimens from the Burgess Shale are currently undergoing a detailed re-study and some specimens will doubtlessly be reclassified into other chancelloriid genera (Bengtson and Collins, 2009).

Description:

Morphology:

Chancelloria resembled a cylindrical cactus up to 20 centimetres tall. An assortment of star-shaped spines constitutes a loose and unconnected net arranged in various fashions. These spines formed a tight ring around the top of the organism, which seems to have surrounded a pore. Water would probably have passed through this opening and any organic particles would have been filtered out for food.

The spicules of Chancelloria, which varied from millimetric to about a centimetre in diameter, were composed of hollow rays that were stuck together at a central point to form a three-dimensional structure shaped like an umbrella. A central ray pointed out from the organism, and other rays radiating outwards at an angle closer to the surface of the organism, presumably to aid in defence. The nature of the rays distinguishes between the chancelloriid genera and species; C. eros bears four to seven rays per spicule. The closely related Allonnia is differentiated from Chancelloria by its more globular shape and the details of its sclerite construction, which consists of three main rays. A third genus, Archiasterella, is also represented in the Burgess Shale and differs from the two other genera in sclerite morphology and numbers of rays.

Abundance:

Chancelloria accounts for under 0.5% of the Burgess Shale community (Caron and Jackson, 2008), including specimens that may belong to Allonnia or Archiasterella.

Maximum Size:
200 mm

Ecology:

Life habits: Raymond Quarry
Feeding strategies: Raymond Quarry
Ecological Interpretations:

Chancelloria primarily attached itself to organisms, commonly sponges or other chancelloriids, but also on occasion to shell fragments that may have been partially buried in the sea floor. It remained in this anchored position and fed by extracting particles from seawater, which it sucked in and squeezed out through an opening in the top of its body. It spines probably served as a defence against predators.

References:

BENGTSON, S. 2005. Mineralized skeletons and early animal evolution, p. 101-124. In D. E. G. Briggs (ed.), Evolving form and function: fossils and development. Proceedings of a symposium honoring Adolf Seilacher for his contributions to paleontology, in celebration of his 80th birthday. Peabody Museum of Natural History, New Haven, Connecticut.

BENGTSON, S. AND D. COLLINS. 2009. Burgess Shale Chancelloriids – A Prickly Problem. International Conference on the Cambrian Explosion (Walcott 2009), Banff.

BENGTSON, S. AND X. HOU. 2001. The integument of Cambrian chancelloriids. Acta Palaeontologica Polonica, 46: 1-22.

BENGTSON, S. AND V. V. MISSARZHEVSKY. 1981. Coeloscleritophora-a major group of enigmatic Cambrian metazoans. United States Geological Survey Open-file Report, 81-743: 19-21.

BERESI, M. S. AND J. K. RIGBY. 1994. Sponges and Chancelloriids from the Cambrian of Western Argentina. Journal of Paleontology, 68: 208-217.

BRASIER, M. D. 1984. Microfossils and small shelly fossils from the Lower Cambrian Hyolithes Limestone at Nuneaton, English Midlands. Geological Magazine, 121: 229-253.

BUTTERFIELD, N. J. AND C. J. 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.

ELLIOTT, D. K. AND D. L. MARTIN. 1987. Chancelloria, an Enigmatic Fossil from the Bright Angel Shale (Cambrian) of Grand Canyon, Arizona. Journal of the Arizona-Nevada Academy of Science, 21: 67-72.

GORYANSKY, V. Y. 1973. O neobkhodimosti isklucheniya roda Chancelloria Walcott iz tipa gubok. [On the necessity of exclusion of Chancelloria Walcott from the phylum Porifera.] Trudy Institute Geologia; Geofizika Sibirskoye Otdeieniye 49: 34-44. [in Russian].

HOHENSEE, S. R. AND J. H. STITT. 1989. Redeposited Elvinia Zone (Upper Cambrian) trilobites from the Collier Shale, Ouachita Mountains, west-central Arkansas. Journal of Paleontology, 63: 857-879.

JANUSSEN, D. M. STEINER, AND Z. MAOYAN. 2002. New well-preserved scleritomes of Chancelloridae from the Early Cambrian Yuanshan Formation (Chengjiang, China) and the Middle Cambrian Wheeler Shale (Utah, USA) and paleobiological implications. Journal of Paleontology, 76: 596-606.

LANDING, E. 1991. Upper Precambrian through Lower Cambrian of Cape Breton Island: Faunas, Paleoenvironments, and Stratigraphic Revision. Journal of Paleontology, 65: 570-595.

LAURIE, J. R. 1986. Phosphatic fauna of the Early Cambrian Todd River Dolomite, Amadeus Basin, central Australia. Alcheringa: An Australasian Journal of Palaeontology, 10: 431-454.

MASON, J. F. 1938. Cambrian Faunal Succession in Nevada and California. Journal of Paleontology, 12: 287-294.

PORTER, S. M. 2008. Skeletal microstructure indicates Chancelloriids and Halkieriids are closely related. Palaeontology, 51: 865-879.

RANDELL, R. D., B. S. LIEBERMAN, S. T. HASIOTIS, AND M. C. POPE, 2005. New chancelloriids from the Early Cambrian Sekwi Formation with a comment on chancelloriid affinities. Journal of Paleontology, 79: 987-996.

REID, R. E. H. 1959. Occurrence of Chancelloria Walcott in the Comley Limestone. Geological Magazine, 96: 261-262.

RIGBY, J. K. 1978. Porifera of the Middle Cambrian Wheeler Shale, from the Wheeler Amphitheater, House Range, in Western Utah. Journal of Paleontology, 52: 1325-1345.

SARMIENTO, G. N., D. FERNÁNDEZ REMOLAR, AND M. CEMAL GONCÜOGLU. 2001. Cambrian small shelly fossils from the Çal Tepe Formation, Taurus Mountains, Turkey. Coloquios de paleontología:117.

SKOVSTED, C. B. AND J. S. PEEL. 2007. Small shelly fossils from the argillaceous facies of the Lower Cambrian Forteau Formation of western Newfoundland. Acta Palaeontologica Polonica, 52: 729.

WALCOTT, C. D. 1920. Cambrian geology and paleontology. IV. Middle Cambrian Spongiae. Smithsonian Miscellaneous Collections, 67: 261-364.

WRONA, R. 2004. Cambrian microfossils from glacial erratics of King George Island, Antarctica. Acta Palaeontologica Polonica, 49: 13-56.

Other Links:

None