The Burgess Shale

Mount Stephen: Trilobite Beds

Elrathina cordillerae

Elrathina cordillerae (ROM 53273). Complete individual; a presumed carcass with free cheeks in place (coated with ammonium chloride sublimate to show details). Specimen length = 24 mm. Specimen dry – direct light. Mount Stephen Trilobite Beds on Mount Stephen.

© Royal Ontario Museum. Photo: Jean-Bernard Caron

Taxonomy:

Kingdom: Trilobite Beds
Phylum: Trilobite Beds
Higher Taxonomic assignment: Trilobita (Order: Ptychopariida)
Species name: Elrathina cordillerae
Remarks:

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

Described by: Rominger
Description date: 1887
Etymology:

Elrathina – unspecified.

cordillerae – in reference to the Western Cordillera (Canadian Rocky Mountain ranges), derived from the Spanish cordilla, the diminutive of cuerda, meaning “cord.”

Type Specimens: Type status under review – UMMP 4883 (6 specimens), University of Michigan Museum of Paleontology, Ann Arbor, Michigan, USA.
Other species:

Burgess Shale and vicinity: Elrathina parallela, E. brevifrons, E. spinifera, and E. marginalis have been described from similar stratigraphic horizons at nearby sites on Mount Field, Mount Stephen, and Mount Odaray.

Other deposits: Other species of Elrathina have been reported from the Cambrian of North America and Greenland.

Age & Localities:

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

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

History of Research:

Brief history of research:

E. cordillerae was originally described under the genus name Conocephalites in Rominger’s 1887 publication on trilobites from Mount Stephen. In 1888 Walcott reallocated the species to Ptychoparia where it remained until Charles Resser, Walcott’s former assistant at the United States National Museum, established the new replacement genus Elrathina (Resser, 1937). Other workers have subsequently suggested that Elrathina is indistinguishable from Ptychoparella (see Blaker and Peel, 1997).

Species of Elrathina, along with those of the corynexochid Bathyuriscus, were found to be very abundant in a narrow interval of Middle Cambrian rocks throughout western North America, forming the basis of the Bathyuriscus-Elrathina Zone erected by Charles Deiss (1940).

Description:

Morphology:

Hard parts: adult dorsal exoskeletons average about 2 cm long. The semicircular cephalon is about one-third the length of the entire dorsal shield, bordered by a well-defined narrow rim, and with rounded genal angles. Weak transverse eye ridges extend to the small eyes, which are located just forward of cephalic mid-length. The slightly anteriorly narrowing glabella is rounded in front and exhibits three pairs of shallow lateral furrows; the pre-glabellar field is about the same width as the narrow anterior rim. The long, tapering thorax with a narrow axial lobe contains between 17 and 19 straight-sided segments, flexed gently downwards a short distance from the rounded tips. The tiny elliptical pygidium usually features two segments.

Unmineralized anatomy: rare specimens from the Walcott Quarry on Fossil Ridge retain tantalizing evidence of soft parts, including a pair of slender uniramous antennae, followed by very delicate looking biramous limbs beneath the cephalon, thorax and pygidium. These and other individuals of E. cordillerae are occasionally associated with a dark stain adjacent to the exoskeleton, presumably representing fluidized decay products.

Abundance:

Relatively common on Fossil Ridge and locally very abundant in the Walcott Quarry, where it represents about 25% of all trilobites collected (Caron and Jackson, 2008).

Maximum Size:
28 mm

Ecology:

Life habits: Trilobite Beds
Feeding strategies: Trilobite Beds
Ecological Interpretations:

Like similar-looking ptychoparioid trilobites, E. cordillerae may be interpreted as a fully mobile, epibenthic deposit (particle) feeder adapted to very low oxygen levels.

References:

BLAKER, M. R. AND J. S. PEEL. 1997. Lower Cambrian trilobites from North Greenland. Meddeleser om Grønland, Geoscience, 35, 145 p.

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

DEISS, C. 1940. Lower and Middle Cambrian stratigraphy of southwestern Alberta and southeastern British Columbia. Bulletin of the Geological Society of America, 51: 731-794.

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.

ROMINGER, C. 1887. Description of primordial fossils from Mount Stephens, N. W. Territory of Canada. Proceedings of the Academy of Natural Sciences of Philadelphia, 1887: 12-19.

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.

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

Other Links:

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

http://www.geological-supplies.com/burgess/abstracts/balint

http://gsa.confex.com/gsa/2008AM/finalprogram/abstract_149017.htm

Eiffelospongia hirsuta

Eiffelospongia hirsuta (ROM 43828) – Holotype. Specimen with well preserved bearded root tuft. Specimen height = 8 mm. Specimen dry – direct light (left), wet – polarized light (right). Trilobite Beds on Mount Stephen.

© Royal Ontario Museum. Photos: Jean-Bernard Caron

Taxonomy:

Kingdom: Trilobite Beds
Phylum: Trilobite Beds
Higher Taxonomic assignment: Calcarea (Order: Heteractinida)
Species name: Eiffelospongia hirsuta
Remarks:

This species resembles Diagoniella but belongs to sponges with calcium carbonate (calcite or aragonite) spicules (Rigby and Collins, 2004).

Described by: Rigby and Collins
Description date: 2004
Etymology:

Eiffelospongia – from the nearby Eiffel Peak, named on account of its resemblance to Paris’ Eiffel Tower, and spongia, the Latin word meaning “sponge.”

hirsuta – from the Latin hirtus, “hairy,” referring to the hairy or beard-like appearance of the basal tuft and dermal layer of this species.

Type Specimens: Holotype –ROM43828 (wrongly referencedROM48828 in Rigby and Collins, 2004), 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 Trilobite Beds on Mount Stephen.

History of Research:

Brief history of research:

This genus was named by Rigby and Collins in 2004 based on new material collected from the Trilobite Beds on Mount Stephen by the Royal Ontario Museum.

Description:

Morphology:

Eiffelospongia is a small (less than 1 cm) oval or keg-shaped sponge with a large central cavity and a small osculum (opening at the top) with a flat margin. The skeleton of Eiffelospongia is composed of two orders of spicules: long thin-rayed spicules with six-pointed ends (hexaradiate), that thatch together to give shape to the sponge, and a second type of spicules which are much smaller and occur in the spaces between the long spicules. The basal part of the sponge is defined by long coarse spicules, arranged lengthways, that form a triangular tuft shape.

Abundance:

The species is known from only a few specimens from the Trilobite Beds on Mount Stephen.

Maximum Size:
10 mm

Ecology:

Life habits: Trilobite Beds
Feeding strategies: Trilobite Beds
Ecological Interpretations:

Eiffelospongia would have lived with its bearded root tuft 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:

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.

Other Links:

None

Eiffelia globosa

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

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Kingdom: Trilobite Beds
Phylum: Trilobite Beds
Higher Taxonomic assignment: Calcarea (Order: Heteractinida)
Species name: Eiffelia globosa
Remarks:

Eiffelia is thought to fall near the divergence of the calcareous and hexactinellid sponges (Botting and Butterfield, 2005).

Described by: Walcott
Description date: 1920
Etymology:

Eiffelia – from the nearby Eiffel Peak, named on account of its resemblance to Paris’ Eiffel Tower. The tower bears the name of Alexandre Gustave Eiffel (1832-1923), a French engineer famous for building many large steel structures.

globosa – from the Latin globus, “globe or ball,” reflecting the organism’s shape.

Type Specimens: Lectotype –USNM66522, in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: E. araniformis Missarzhevsky and Mambetov, 1981 from several Early Cambrian small shelly fossil deposits (Bengtson et al., 1990; Skovsted, 2006).

Age & Localities:

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

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

History of Research:

Brief history of research:

Originally described by Walcott in 1920, little research concentrated on Eiffelia until it was re-described by Rigby in 1986 as part of his review of Burgess Shale sponges. Additional specimens collected by the Royal Ontario Museum were described subsequently by Rigby and Collins (2004). Bearing characteristics of both the calcareous and hexactinellid sponges, Eiffelia has been important in determining higher-level evolutionary relationships within the sponges. Eiffelia spicules form by the accretion of phosphate on a siliceous core, which provides a possible evolutionary transition between the minerals used in the construction of spicules (Botting and Butterfield, 2005)

Description:

Morphology:

Eiffelia is usually preserved as a flattened net of spicules within a single layer, forming a mesh with an approximately circular outline 1 to 6 cm in diameter. Spicules occur in at least five distinct size ranges. The largest ones usually take the form of six-pointed stars (hexaradiate), whereas the smallest ones usually have only four-pointed ends. The rays generally run parallel to one another, producing a somewhat geometric lattice-like appearance. The largest spicules, spaced a few millimetres apart from one another, enclose spicules of the second size class between their slender tapering rays. The smaller spicules, which are so small as to rarely be preserved, fill the remaining gaps in the mesh. The spicules themselves are joined by a small central disc formed from flared-out sections of their bases at the point where the six spines meet. Eiffelia’s spicules supported a thin wall that would have formed an orb-shaped sac perforated with occasional small elliptical openings (ostia).

Abundance:

Relatively rare in the Walcott Quarry where it represents only 0.1% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
60 mm

Ecology:

Life habits: Trilobite Beds
Feeding strategies: Trilobite Beds
Ecological Interpretations:

The sponge sat on the sea floor possibly sticking on hard surfaces. Particles of organic matter were extracted from the water as they passed through canals in the sponge’s wall.

References:

BENGTSON, S. S. CONWAY MORRIS, B. J. COOPER, P. A. JELL AND B. N. RUNNEGAR. 1990. Early Cambrian fossils from South Australia, 9, 364 p.

BOTTING, J. P. AND N. J. BUTTERFIELD. 2005. Reconstructing early sponge relationships by using the Burgess Shale fossil Eiffelia globosa, Walcott. Proceedings of the National Academy of Sciences, 102(5): 1554.

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

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

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: 1-155.

SKOVSTED, C. B. 2006. Small shelly fauna from the Upper Lower Cambrian Bastion and Ella Island Formations, North-East Greenland. Journal of Paleontology, 80:1087-1112.

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

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: Trilobite Beds
Phylum: Trilobite Beds
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: Trilobite Beds
Feeding strategies: Trilobite Beds
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: Trilobite Beds
Phylum: Trilobite Beds
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: Trilobite Beds
Feeding strategies: Trilobite Beds
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: Trilobite Beds
Phylum: Trilobite Beds
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: Trilobite Beds
Feeding strategies: Trilobite Beds
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: Trilobite Beds
Phylum: Trilobite Beds
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: Trilobite Beds
Feeding strategies: Trilobite Beds
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

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: Trilobite Beds
Phylum: Trilobite Beds
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: Trilobite Beds
Feeding strategies: Trilobite Beds
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: Trilobite Beds
Phylum: Trilobite Beds
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: Trilobite Beds
Feeding strategies: Trilobite Beds
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: Trilobite Beds
Phylum: Trilobite Beds
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: Trilobite Beds
Feeding strategies: Trilobite Beds
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