The Burgess Shale

Others: Others

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: Others
Phylum: Others
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: Others
Feeding strategies: Others
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

Diagoniella hindei

3D animation of Diagoniella cyathiformis and other sponges (Choia ridleyi, 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: Others
Phylum: Others
Higher Taxonomic assignment: Hexactinellida (Order: Reticulosa)
Species name: Diagoniella hindei
Remarks:

Diagoniella is placed in the Family Protospongiidae (primitive hexactinellids) and may be confused with Protospongia (Rigby, 1986). Hexactinellid sponges (glass sponges) have a skeleton composed of four to six-pointed siliceous spicules. They are considered to be an early branch within the Porifera phylum due to their distinctive composition.

Described by: Walcott
Description date: 1920
Etymology:

Diagoniella – from the Greek dia, “throughout, during or across”, and gon, “corner, joint or angle” refering to the diagonal spicules of this sponge.

hindei – for Dr. G. J. Hinde, a British palaeontologist who worked on fossil sponges.

Type Specimens: Lectotype –USNM66503 (D. hindei), in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. (D. cyathiformis type and repository information unknown.)
Other species:

Burgess Shale and vicinity: D. cyathiformis (Dawson, 1889) from the Trilobite Beds and Tulip Beds on Mount Stephen, Walcott Quarry on Fossil Ridge and Stanley Glacier (Caron et al., 2010).

Other deposits: D. coronata Dawson, 1890 from the Ordovician of Québec at Little Métis.

Age & Localities:

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

Burgess Shale and vicinity: This sponge has been found at the Walcott Quarry on Fossil Ridge, the Trilobite Beds and Tulip Beds (S7) localities on Mount Stephen and from Stanley Glacier in Kootenay National Park.

Other deposits: D. cyathiformis (Dawson, 1889) from the Ordovician of Québec at Little Métis to the Middle Cambrian Wheeler and Marjum Formations in Utah (for D. cyathiformis) D. hindei Walcott, 1920 from the Cambrian of Utah and Nevada as well (Rigby, 1978, 1983).

History of Research:

Brief history of research:

Diagoniella was described by Rauff in 1894 as a subgenus of Protospongia. Walcott described a new species, D. hindei, in his 1920 monograph of the sponges from the Burgess Shale and made Diagoniella a valid genus, considering it distinct from Protospongia. Ribgy (1986) restudied the sponges of the Burgess Shale including D. hindei and Rigby and Collins (2004) concluded that another species, known in other Cambrian deposits, D. cyathiformis, is also present in the Burgess Shale.

Description:

Morphology:

D. hindei is a small and simple conical sac-like sponge. The skeleton is composed of diagonally orientated coarse spicules along the length of the sponge. These spicules are known as stauracts, and differ from the normal six rayed spicules of the hexactinellid sponges in that they have two rays reduced which gives them a distinctive cross-shape. The spicules knit together to form a net, although, unlike some hexactinellid sponges this net is not fused, which make the sponges very delicate. D. cyathiformis is a larger (up to 120 mm) and more elongate, conical species. The long spicules form a tuft-like root structure at the base of the sponge.

Abundance:

Diagoniella is relatively common but represents only 0.24% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
18 mm

Ecology:

Life habits: Others
Feeding strategies: Others
Ecological Interpretations:

Diagoniella 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.

CARON, J.-B., R. GAINES, G. MANGANO, M. STRENG AND A. DALEY. 2010. A new Burgess Shale-type assemblage from the “thin” Stephen Formation of the Southern Canadian Rockies. Geology, 38: 811-814.

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.

RIGBY, J. K. 1983. Sponges of the Middle Cambrian Marjum Limestone from the House Range and Drum Mountains of Western Millard County, Utah. Journal of Paleontology, 57: 240-270.

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:

None

Paterina zenobia

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

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: Others
Phylum: Others
Higher Taxonomic assignment: Paterinata (Order: Paterinida)
Species name: Paterina zenobia
Remarks:

A brachiopod within the family Paterinidae.

Described by: Walcott
Description date: 1912
Etymology:

Paterina – from the Latin word pater, “father,” because the species was considered the ancestor of modern brachiopods, and the diminutive suffix, – ina, “derived from.”

zenobia – possibly from the Greek, Zeon, a form of Zeus.

Type Specimens: Syntype–USNM58311; plesiotypesUSNM56907, 51483, 69631- 69637 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 the Lower to the Middle Cambrian worldwide.

Age & Localities:

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

The Walcott Quarry on Fossil Ridge and the Trilobite Beds on Mount Stephen.

History of Research:

Brief history of research:

Walcott originally assigned specimens collected from the Burgess Shale and Mount Stephen to Micromitra zenobia Walcott (1912) and a subspecies of Paterina stissingensis, called Paterina stissingensis ora Walcott (1912). Both taxa were redescribed as Paterina zenobia by Resser (1938), a combination still in use today. However, close similarities between species of the two genera have created difficulties in defining their specific characteristics, which have resulted in many incorrectly identified specimens.

Description:

Morphology:

Paterina is the type genus of one of the earliest and most primitive brachiopod groups, the Paterinata. Unlike many modern brachiopods, its hinge line is straight and crosses almost the full width of the shell. The moderately biconvex shell grows consistently, rather than showing separate stages of development. Its exterior growth lines are coarse and regular. Faint radial ridges are present at the apex of some adult specimens. No preserved soft parts are known and the shell was originally mineralized.

Abundance:

This species is rare in the Walcott Quarry and represents a very small fraction of the entire fauna (<0.05%) (Caron and Jackson, 2008).

Maximum Size:
11 mm

Ecology:

Life habits: Others
Feeding strategies: Others
Ecological Interpretations:

Paterina probably attached to the substrate by a very short stalk. Paterina extracted food particles from the water with its filter-feeding apparatus (located between the shells) called a lophophore.

References:

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

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

WALCOTT, C. D. 1912. Cambrian Brachiopoda. United States Geological Survey, Monograph, 51: part I, 812 p; part II, 363 p.

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: Others
Phylum: Others
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: Others
Feeding strategies: Others
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: Others
Phylum: Others
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: Others
Feeding strategies: Others
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: Others
Phylum: Others
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: Others
Feeding strategies: Others
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

Oryctocephalus reynoldsi

Oryctocephalus burgessensis (ROM 49962). Complete small individual; a presumed carcass with free cheeks in place. Specimen length = 5.5 mm. Specimen dry – direct light (left) and coated with ammonium chloride sublimate to show details (right). Walcott Quarry talus.

© ROYAL ONTARIO MUSEUM. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Others
Phylum: Others
Higher Taxonomic assignment: Trilobita (Order: Corynexochida)
Species name: Oryctocephalus reynoldsi
Remarks:

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

Described by: Reed
Description date: 1899
Etymology:

Oryctocephalus – from the Greek oryktos, “dug” or “burrowed,” and kephalos, “head.”

reynoldsi – after Mr. S. H. Reynolds, who collected and donated the type specimen to the Woodwardian Museum of the University of Cambridge (now in the Sedgwick Museum of Earth Sciences).

Type Specimens: Holotype (O. reynoldsi) – SM A1425, Sedgwick Museum of Earth Sciences, University of Cambridge, Cambridge, UK. Holotype S17 (O. burgessensis) –USNM96487, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: Oryctocephalus burgessensis Resser, 1938.

Other deposits: many other species worldwide.

Age & Localities:

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

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

History of Research:

Brief history of research:

The genus Oryctocephalus was established by Charles Walcott in 1886 to include the species O. primus, based on isolated cranidia and pygidia from the Middle Cambrian of Nevada. Reed named and described O. reynoldsi in 1899 from a complete specimen (including the articulated thorax), probably collected at the Mount Stephen Trilobite Beds. In the same year as Reed’s paper appeared, G. F. Matthew also had a publication in press, describing O. walkeri from collections on Mount Stephen. Although minor differences between O. reynoldsiand O. walkeri were noted (Matthew, 1899), they are almost certainly one and the same, and Reed’s name has publication priority. In 1938, Resser erected a new species, O. burgessensis, for specimens from the Walcott Quarry. Rasetti (1951) illustrated O. reynoldsiand O. burgessensis and named another new species, O. matthewi, from both localities. Whittington reassessed the Burgess Shale species of Oryctocephalus in 1995, and found that Rasetti’s O. matthewi was indistinguishable from O. reynoldsi.

Description:

Morphology:

Hard parts: both Oryctocephalus reynoldsi and O. burgessensis are small trilobites, with adult exoskeletons generally 15-20 mm long, excluding pygidial spines. Dorsal shields are ovoid in outline, slightly narrower posteriorly. O. reynoldsi has a broad semicircular cephalon, with the genal angles drawn out and back into long slender spines extending almost to the pygidium. The distinctive glabella widens slightly forwards to a rounded front at the anterior border. Three pairs of pits lie forward of the occipital ring, just inside the axial furrows; the posterior pair is joined by a shallow transverse furrow. Faint eye ridges swing back from near the front of the glabella to the long crescentic eye lobes far out on the cheeks. The thorax contains seven wide segments with strong, curving pleural furrows and long terminal spines directed obliquely rearward. The unmistakable pygidium is semicircular, narrower than the cephalon, with a tapering axis of five rings and a terminal piece ending well inside the posterior margin. Six radially disposed pleurae all end in spines, the fourth pair being much broader at the base and very long, directed out and back to at least twice the length of the pygidium. The short fifth and sixth spine pairs extend straight back. O. burgessensis can be distinguished mainly by its subtly shorter genal and fourth pygidial spines; the genal spine also appears to arise slightly farther forward than in O. reynoldsi.

Unmineralized anatomy: not known

Abundance:

Rare, both on Mount Stephen and on Fossil Ridge.

Maximum Size:
25 mm

Ecology:

Life habits: Others
Feeding strategies: Others
Ecological Interpretations:

Very similar species of Oryctocephalus are found in Middle Cambrian rocks of deeper water origin in many places around the world, suggesting that these cosmopolitan trilobites typically inhabited open ocean settings.

References:

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, Vol. 5, Section IV: 39-66.

RASETTI, F. 1951. Middle Cambrian stratigraphy and faunas of the Canadian Rocky Mountains. Smithsonian Miscellaneous Collections, 116 (5): 1-277.

REED, F. R. C. 1899. Woodwardian Museum Notes: a new trilobite from Mount Stephen, Field, B.C. Geological Magazine, New Series (Decade 4), 6: 358-361.

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

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. 1886. Second contribution to the studies on the Cambrian faunas of North America. Bulletin of the US Geological Survey, 30: 1-255.

WHITTINGTON, H. B. 1995. Oryctocephalid trilobites from the Cambrian of North America. Palaeontology, 38: 543-562.

Other Links:

None

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: Others
Phylum: Others
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: Others
Feeding strategies: Others
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: Others
Phylum: Others
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: Others
Feeding strategies: Others
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

Caryosyntrips serratus

Caryosyntrips serratus (ROM 57161) – Holotype, part and counterpart. Individual claw. Specimen length = 78 mm. Specimen dry – direct light (top row), dry – polarized light (bottom row). Walcott Quarry.

© Royal Ontario Museum. Photo: Jean-Bernard Caron

Taxonomy:

Kingdom: Others
Phylum: Others
Higher Taxonomic assignment: Dinocarida (Order: Radiodonta, stem group arthropods)
Species name: Caryosyntrips serratus
Remarks:

Caryosyntrips is an anomalocaridid. Anomalocaridids have been variously regarded as basal stem-lineage euarthropods (e.g., Daley et al., 2009), basal members of the arthropod group Chelicerata (e.g., Chen et al., 2004), and as a sister group to the arthropods (e.g., Hou et al., 2006).

Described by: Daley and Budd
Description date: 2010
Etymology:

Caryosyntrips – from the Greek karyon meaning “nut,” and syntrips, a mythical fiend who smashed pottery; thus, a nut smasher, referring to the nutcracker-like morphology of the paired appendages

serratus – from the Latin serratus, “saw-edged.”

Type Specimens: Holotype –ROM57161 in the Royal Ontario Museum, Toronto, Canada.
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 and Raymond Quarries on Fossil Ridge. Also known from the Tulip Beds (S7) on Mount Stephen.

History of Research:

Brief history of research:

This genus was first noticed and illustrated as “Dinocarida A” in Caron (2005), and formally designated as Carysyntrips serratus by Daley and Budd (2010).

Description:

Morphology:

This taxon is known from eleven specimens of isolated appendages. Appendages are straight and tapering in outline, with a length that ranges between 58 mm and 114 mm. Segmentation of the appendage is poor, but at least 12 podomeres (segments) can be distinguished. The appendage is straight and rigid, with no movement occurring at the podomere boundaries. Each podomere has one thick, short spine on the inner surface, and several smaller spines on the outer surface, giving this outer margin a serrated appearance. The distal end of the appendage tapers to a point, and a single terminal spine is slightly curved. Most appendages are isolated, but a single paired specimen shows the appendages arranged in close proximity, with their thick spine margins in opposition. This particular specimen is loosely associated with potential remains of the body of the animal in the form of some cuticular elements. However, these elements are poorly preserved and might not be of the same animal.

Abundance:

Carysyntrips serratus is extremely rare. Most specimens (8) come from the Walcott Quarry.

Maximum Size:
114 mm

Ecology:

Life habits: Others
Feeding strategies: Others
Ecological Interpretations:

Carysyntrips serratus is assumed to have had a similar mode of life to the rest of the anomalocaridids, meaning that it swam through the water column actively searching out prey. Its predatory nature is inferred from the morphology of the appendages, which were heavily spined. The straight, rigid appendages may have pivoted at their proximal attachment points to bring the thick-spine edges of the pair appendages together in a grasping or slicing motion.

References:

CARON, J. B. 2005. Taphonomy and community analysis of the Middle Cambrian Greater Phyllopod Bed, Brugess Shale. Unpublished Ph.D. thesis, University of Toronto, Toronto, 316 pp.

CHEN, J. Y. D. WALOSZEK AND A. MAAS. 2004. A new ‘great-appendage’ arthropod from the Lower Cambrian of China and homology of chelicerate chelicerae and raptorial antero-ventral appendages. Lethaia, 37: 3-20.

DALEY, A. C., G. E. BUDD, J. B. CARON, G. D. EDGECOMBE AND D. COLLINS. 2009. The Burgess Shale anomalocaridid Hurdia and its significance for early euarthropod evolution. Science, 323: 1597-1600.

DALEY, A. C. AND G. E. BUDD. 2010. New anomalocaridid appendage from the Burgess Shale, Canada. Palaeontology, 53: 721-738.

Other Links:

None