The Burgess Shale

Wapkia grandis

3D animation of Wapkia elongata and other sponges (Choia ridleyiDiagoniella cyathiformisEiffelia globosaHazelia confertaPirania muricata, and Vauxia bellula) and Chancelloria eros a sponge-like form covered of star-shaped spines.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Demospongia (Order: Monaxonida)
Species name: Wapkia grandis
Remarks:

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

Described by: Walcott
Description date: 1920
Etymology:

Wapkia – origin of name is unknown

grandis – from the Latin grandis, “large.” This name refers to the large size and complex skeleton of this sponge.

Type Specimens: Lectotype –USNM66458 (W. grandis), in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. Holotype –ROM53544 (W. elongata), in the Royal Ontario Museum, Toronto, Canada.
Other species:

Burgess Shale and vicinity: W. elongata Rigby and Collins, 2004 from the Tulip Beds (S7) on Mount Stephen.

Other deposits: none.

Age & Localities:

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

The Walcott Quarry on Fossil Ridge. The Tulip Beds (S7) on Mount Stephen.

History of Research:

Brief history of research:

Wapkia was described by Walcott in his initial description of the Burgess Shale sponges in 1920. The genus was re-examined by Rigby in 1986. Rigby and Collins (2004) also redescribed the genus and proposed a new species, W. elongata.

Description:

Morphology:

Wapkia is a large elongate or oval sponge with bundles of coarse and fine spicules aligned in long vertical columns and distinct horizontal bundles. The surface of the sponge is smooth and lacks any vertical or horizontal ridges. Spicules are straight and pointed at both ends (oxeas). The exact position of the various bundles of spicules in the skeleton is still uncertain, but it seems that the inner part of the skeleton is reticulate with horizontal wrinkles that are typical of the species and produced by horizontal bundles of spicules. The dermal layer is formed by bundles of oxeas up to 60 mm long which give a characteristic plumose aspect to this sponge. W. elongata is distinguished from W. grandis based on the overall shape of the sponge and different skeletal structures (varying distance between the horizontal spicule bundles).

Abundance:

Wapkia is rare and represents only 0.06% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
170 mm

Ecology:

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

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

References:

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

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

RIGBY, J. K. 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.

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Walcottidiscus typicalis

Walcottidiscus typicalis (GSC 45368). Complete but poorly preserved specimen. Specimen diameter = 18 mm. Specimen dry – direct light. Walcott Quarry.

© GEOLOGICAL SURVEY OF CANADA. PHOTO: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Edrioasteroidea (Order: Edrioasteroida, stem group echinoderms)
Species name: Walcottidiscus typicalis
Remarks:

Walcottidiscus is a poorly known edrioasteroid, an extinct group of echinoderms (Smith, 1985).

Described by: Bassler
Description date: 1935
Etymology:

Walcottidiscus – from Charles Walcott, the discoverer of the Burgess Shale, and the Greek diskos, “disc.” The name refers to the flattened appearance of the fossils.

typicalis – from the Greek typikos, “type,” perhaps in reference to the single specimen originally described.

Type Specimens: Holotype –USNM90754 (W. typicalis),USNM90755 (W. magister) in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: W. magister Bassler, 1935 from the Walcott Quarry on Fossil Ridge (but see below paragraph brief history of research).

Other deposits: none.

Age & Localities:

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

The Walcott Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Two species known from a single specimen each were originally described by Bassler in 1935 and 1936: a small form W. typicalis, and a larger form W. magister respectively. However, W. magister is now thought to belong to W. typicalis (Smith, 1985) but additional fossil material would be required to confirm this hypothesis. Walcottidiscus resembles Kailidiscus chinensis, a chinese form from the Middle Cambrian Kaili deposit, but remains too poorly known to draw more detailed comparisons between the two genera (Zhao et al., 2010).

Description:

Morphology:

The body (theca) is ovoid in outline and has a relatively small dorsal surface compared to the ventral one. The upper central part of the theca is not calcified, but the outer zone is composed of small calcified plates. A five star-shaped food groove lined with small plates (the ambulacra) is present on the upper surface. The five arms of the ambulacra are arranged in a 2:1:2 fashion around the mouth, and they are at first straight and then turn to the left near the edge of the theca. Differences between the two species are the size and degree of ambulacral curvature, but those differences could simply be a factor of growth.

Abundance:

Walcottidiscus is very rare only two specimens were originally described. A few additional specimens are known in the Burgess Shale collections of the Geological Survey of Canada and the Royal Ontario Museum.

Maximum Size:
64 mm

Ecology:

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

Walcottidiscus was most likely resting on the seafloor. Food particles were transported by food grooves (ambulacrum) into a central mouth at the top of the theca.

References:

BASSLER, R. S. 1935. The classification of the Edrioasteroidea. Smithsonian Miscellaneous Collections, 93: 1-11.

BASSLER, R. S. 1936. New species of American Edrioasteroidea. Smithsonian Miscellaneous Collections, 95: 1-33.

SMITH, A. B. 1985. Cambrian eleutherozoan echinoderms and the early diversification of edrioasteroids. Palaeontology, 28: 715-756.

ZHAO, Y., C. D. SUMRALL, R. L. PARSLEY AND J. I. N. PENG. 2010. Kailidiscus, a new plesiomorphic edrioasteroid from the basal Middle Cambrian Kaili biota of Guizhou province, China. Journal of Paleontology, 84: 668-680.

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Wahpia insolens

Wahpia insolens (USNM 35424) – Syntype. Specimen showing typical mode of branching. Specimen length = 90 mm. Specimen wet – direct light (left), polarized light (right). Trilobite Beds on Mount Stephen.

© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Non applicable
Species name: Wahpia insolens
Remarks:

No revisions of this alga have been published since its original description by Walcott (1919) and its affinities remain uncertain.

Described by: Walcott
Description date: 1919
Etymology:

Wahpia – unspecified.

insolens – from the Latin insolens, “unusual, different.” This probably refers to the unusual branches of this alga.

Type Specimens: Syntypes –USNM35423-35424 (W. insolens); Holotypes –USNM35413 (W. mimica);USNM35425 (W. virgata) in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: W. mimica Walcott, 1919 and W. virgata Walcott, 1919 from the Walcott Quarry.

Other deposits: none.

Age & Localities:

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

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

History of Research:

Brief history of research:

Wahpia was described by Charles Walcott (1919) as a possible red alga. However, like all the algae from the Burgess Shale, it awaits a modern redescription.

Description:

Morphology:

This simple alga has a long central stem with long narrow branches diverging from it at a 45 degree angle; these branches give rise to smaller branches with up to two additional branchings. The central stem is hollow. W. mimica and W. virgata differ from W. insolens based on size differences of the central stem and the number and flexibility of the branches.

Abundance:

Wahpia is very rare and represents only 0.06% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
90 mm

Ecology:

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

The morphology of this alga suggests it was attached to the sea floor rather than being free floating.

References:

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

WALCOTT, C. 1919. Cambrian Geology and Paleontology IV. Middle Cambrian Algae. Smithsonian Miscellaneous Collections, 67(5): 217-260.

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Vauxia gracilenta

3D animation of Vauxia bellula and other sponges (Choia ridleyiDiagoniella cyathiformisEiffelia globosaHazelia confertaPirania muricata, and Wapkia elongata) and Chancelloria eros a sponge-like form covered of star-shaped spines.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Demospongea (Order: Verongida)
Species name: Vauxia gracilenta
Remarks:

Vauxia was placed within the hexactinellids by Walcott in his 1920 original description but Rigby (1980) transferred the genus and family to the Demospongea. Demosponges, the same group that are harvested as bath sponges, represent the largest class of sponges today.

Described by: Walcott
Description date: 1920
Etymology:

Vauxia – from Mount Vaux (3,319 m), a mountain Peak in Yoho National Park, British Columbia. The name refers to William Sandys Wright Vaux (1818-1885) an antiquarian at the British Museum.

gracilenta – from the Latin gracilis, “slender,” referring to the delicate structure of the sponge.

Type Specimens: Lectotypes –USNM66515 (V. gracilenta),USNM66508 (V. bellula),USNM66517 (V. densa),USNM66520 (V. venata), in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. Holotype –ROM53572 (V. irregulara) in the Royal Ontario Museum, Toronto, Canada.
Other species:

Burgess Shale and vicinity: V. bellula Walcott, 1920; V. densa Walcott, 1920; V. irregulara Rigby and Collins, 2004; V. venata Walcott, 1920.

Other deposits: none.

Age & Localities:

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

Burgess Shale and vicinity: Vauxia species are known in the Walcott, Raymond and Collins Quarries on Fossil Ridge, the Trilobite Beds, Tulip Beds (S7) and the Collins Quarry on Mount Stephen, and smaller sites on Mount Field and Odaray Mountain. Vauxia is also known from Monarch in Kootenay National Park.

Other deposits: V. bellula Walcott, 1920 from the Middle Cambrian Wheeler and Marjum Formations in Utah (Rigby et al., 2010); V. magna Rigby, 1980 from the Middle Cambrian Spence Shale in Utah (Rigby, 1980).

History of Research:

Brief history of research:

This sponge was originally described by Walcott in 1920. The genus was reviewed by Rigby (1980) and the species redescribed by Rigby (1986) and Rigby and Collins (2004) in their examination of the Burgess Shale sponges.

Description:

Morphology:

Specimens of Vauxia gracilenta can range from simple unbranched forms to more complex branching forms and reach up to 8 cm in height. Each branch is deeply conical and almost cylindrical, with a simple open central cavity (spongocoel) ending in a rounded of flat opening (osculum). The skeleton is double layered with a thin dermal layer and an inner layer (endosomal). The dermal layer has small openings (ostia) and is composed of a dense network of ladder-like fibers supported by radial fibers from the inner layer. The inner layer forms a regular reticulated net-like skeleton of fibers with 4-6 sided polygons which is characteristic of the genus and species. The fibrous elements (spongin) represent tough collagen proteins. There is no evidence of siliceous spicules in the skeleton.

The different species have been identified mostly based on variations of the skeletal elements and the shape of the branches. Some species can reach up to at least 15 cm in height (V. bellulaV. densa).

Abundance:

Vauxia is relatively common in the Raymond Quarry and other sites on Mount Stephen but is rare in the Walcott Quarry where it represents less than 0.05% of the community (Caron and Jackson, 2008).

Maximum Size:
80 mm

Ecology:

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

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

References:

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

RIGBY, J. K. 1980. The new Middle Cambrian sponge Vauxia magna from the Spence Shale of Northern Utah and taxonomic position of the Vauxiidae. Journal of Paleontology, 54(1): 234-240.

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

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. Cambrian Geology and Paleontology IV. Smithsonian Miscellaneous Collections, 67(6): 261-365.

Other Links:

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Tubulella flagellum

Tubulella flagellum (ROM 59942) – Proposed Lectotype. Figures 1a of Matthew (1899) and photograph of original specimen (right). Approximate specimen length = 80 mm. Specimen dry – direct light. Trilobite Beds on Mount Stephen.

© ROYAL ONTARIO MUSEUM. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Unranked clade (stem group cnidarians)
Species name: Tubulella flagellum
Remarks:

This fossil was originally thought to represent the tube of some sedentary polychaete worms (Matthew, 1899; Howell, 1949), but has more recently been compared to the sessile polyp stage of a scyphozoan jellyfish that builds tapered, chitinous tubes fixed to the substrate by an attachment disc (Van Iten et al., 2002).

Described by: Matthew
Description date: 1899
Etymology:

Tubulella – from the latin tubulus, “tube, or tubule,” and the suffix –ella, denoting “little.”

flagellum – the Latin for “whip,” in allusion to the long, tapering form of the tubular theca.

Type Specimens: Syntype–ROM59942 in the Royal Ontario Museum, Toronto, ON, Canada.
Other species:

Burgess Shale and vicinity: Many shared similarities suggest that other thecate Burgess Shale fossils such as Byronia annulataSphenothallus sp., Cambrorhytium major, and Cfragilis may be related to Tubulella.

Other deposits: Other species occur worldwide in rocks from the Cambrian period.

Age & Localities:

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

The Trilobite Beds, Tulip Beds (S7) and additional smaller localities on Mount Stephen. The Walcott and Raymond Quarries on Fossil Ridge, Mount Odaray and Monarch Cirque.

History of Research:

Brief history of research:

In August 1887 the Toronto meeting of the British Association for the Advancement of Science was followed by a special geological rail tour to western Canada organized by Byron Edmund Walker (a prominent Canadian banker). One of the excursion highlights was a visit to the Mount Stephen Trilobite Beds, after which Walker loaned his personal collection of Mount Stephen fossils to Canada’s leading Cambrian palaeontologist, George F. Matthew, of Saint John, New Brunswick. In 1899, Matthew published a series of new descriptions based on this material, including Urotheca flagellum, a rare form he interpreted as whip-shaped worm tube, illustrated in two engravings. Walker donated these fossils to the University of Toronto in 1904, and in 1913 they were transferred to the new Royal Ontario Museum of Palaeontology. In 1949, American palaeontologist B. F. Howell found that Matthew’s genus name Urotheca was already in use for a living reptile, so he substituted it for the new name Tubulella. Subsequently, this and similar fossils were reinterpreted as cnidarian polyp thecae. The single best specimen of Walker’s Urotheca flagellum remained unrecognized until it was “rediscovered” in the ROM collections in 2010.

Description:

Morphology:

The chitinous or chitinophosphatic tube (theca) of Tubulella flagellum is a very long and slender cone, with a maximum diameter of about 4 mm. The thecae may be almost straight, or show varying degrees of curvature. The thecal wall is relatively thick and often appears densely black against the shale matrix. The external surface shows very fine transverse growth lines, but usually no strong annular ridges. Often, two or more lengthwise creases or ridges were formed as the result of the crushing and compaction of the tube’s original circular or oval cross section. Some specimens possess a combination of features seen in Tubulella and Byronia, with very narrow thecae bearing both annulae and longitudinal creases. Small clusters of such Tubulella-like thecae are occasionally found closely associated with Byronia annulata, but it is not known whether these were asexually generated “buds” or discrete organisms growing attached to the larger tubes. No soft tissues of Tubulella flagellum have been described to date.

Abundance:

Uncommon in the Trilobite Beds on Mount Stephen. Relatively common in the Walcott Quarry on Fossil Ridge where it represents about 0.25% of the specimens in the community (Caron and Jackson, 2008).

Maximum Size:
100 mm

Ecology:

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

The theca of Tubulella was likely attached to the substrate using an apical disc which is usually broken off. The absence of soft tissue preservation makes the assignment to a particular feeding strategy tentative. By comparison with forms such as Cambrorhytium, a carnivorous or suspension feeding habit seems possible.

References:

BISCHOFF, C. O. 1989. Byroniida new order from early Palaeozoic strata of eastern Australia (Cnidaria, thecate scyphopolyps). Senkenbergiana Lethaea, 69(5/6): 467-521.

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

HOWELL, B. F. 1949. New hydrozoan and brachiopod and new genus of worms from the Ordovician Schenectady Formation of New York. Bulletin of the Wagner Free Institute of Science, 24(1): 8 pp.

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

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

VAN ITEN, H., M.-Y. MAO-YAN, AND D.COLLINS 2002. First report of Sphenothallus Hall, 1847 in the Middle Cambrian. Journal of Paleontology, 76: 902-905.

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

ZHU, M.-Y., H. VAN ITEN, R. S. COX, Y.-L. ZHAO AND B.-D. ERDTMANN. 2000. Occurrence of Byronia Matthew and Sphenothallus Hall in the Lower Cambrian of China. Paläontologische Zeitschrift, 74: 227-238.

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Thelxiope palaeothalassia

Thelxiope palaeothalassia (GSC 74990). Articulated specimen (close up to the right), associated with several individuals of the arthropod Canadaspis perfecta. Specimen length = 29 mm. Specimen dry – polarized light. Walcott Quarry.

© GEOLOGICAL SURVEY OF CANADA. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Unranked clade (stem group arthropods)
Species name: Thelxiope palaeothalassia
Remarks:

The affinity of Thelxiope has not been considered in detail because the appendages are unknown.

Described by: Simonetta and Delle Cave
Description date: 1975
Etymology:

Thelxiope – from the Greek thelx meaning “enchanting,” and ops, meaning “voice,” referring to the muse-like appearance of the animal.

palaeothalassia – from the Greek palaios, meaning “ancient,” and thalassios, meaning “marine,” in reference to the age and environment where the animal lived.

Type Specimens: Holotype –USNM144914 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: none.

Age & Localities:

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

The Walcott Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Walcott (1912) figured two fragmentary specimens as Mollisoniarara; these were first reinterpreted by Simonetta (1964) within a new genus Parahabelia rara, along with three additional specimens that he thought were related. However, Simonetta and Delle Cave (1975) considered that among those five specimens, the two originally figured by Walcott as M? rara had to be synonymized with M. symmetrica and the other three had to be placed within a new genus and species called Thelxiope palaeothalassia, a name in use since then.

Description:

Morphology:

This species has a relatively wide cephalon and seven segments and resembles Habelia in overall shape. However, in T. palaeothalassia, each segment bears a single prominent spine pointing dorsally. The last segment is armed with a very long pointed telson.

Abundance:

Thelxiope is extremely rare, with only four known specimens.

Maximum Size:
43 mm

Ecology:

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

Thelxiope is too poorly known to allow detailed studies of its ecology.

References:

SIMONETTA, A. M. 1964. Osservazioni sugli arthropodi non trilobiti della “Burgess Shale” (Cambriano medio). Monitore Zoologico Italiano, 72 (3-4: III Contributo: I Generi MolariaHabeliaEmeraldellaParahabelia (Nov.) Emeraldoides (Nov.): 215-231.

SIMONETTA, A. M. AND L. DELLE CAVE. 1975. The Cambrian non-trilobite arthropods from the Burgess shale of British Columbia: A study of their comparative morphology, taxonomy and evolutionary significance. Palaeontographia Italica, 69: 1-37.

WALCOTT, C. 1912. Cambrian Geology and Paleontology II. Middle Cambrian Branchiopoda, Malacostraca, Trilobita and Merostomata. Smithsonian Miscellaneous Collections, 57(6):145-228.

Other Links:

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Thaumaptilon walcotti

Thaumaptilon walcotti (USNM 468028) – Holotype, part and counterpart. Complete specimen. Specimen height = 212 mm. Specimen dry – direct light (far left and far right), wet – polarized light (middle images). Walcott Quarry.

© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Unranked clade (stem group cnidarians)
Species name: Thaumaptilon walcotti
Remarks:

Thaumaptilon was first interpreted as a Cambrian member of the frondose Ediacaran Biota, related to cnidarians and particularly to a group of modern anthozoans called pennatulaceans or sea pens (Conway Morris, 1993). This connection is no longer widely accepted (Antcliffe and Brasier, 2008); Thaumaptilon has also been proposed as a critical link between Ediacaran fronds and ctenophores (Dzik, 2002). A position in the cnidarian stem group (i.e. more primitive than the anthozoans) has been supported by the discovery of similar fossils in the Chengjiang Biota (Shu et al., 2006).

Described by: Conway Morris
Description date: 1993
Etymology:

Thaumaptilon – from the Greek thauma, “wonderful,” and ptilon, “soft feather,” after its feather-like appearance.

walcotti – after Charles Walcott, discoverer of the Burgess Shale.

Type Specimens: Holotype –USNM468028 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: none.

Age & Localities:

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

The Walcott Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Walcott had studied and photographed Thaumaptilon, but never published his work. The fossil specimens were formally described in 1993 by Conway Morris, who had also alluded to them in previous work (1979; 1989; 1990).

Description:

Morphology:

Thaumaptilon is an oblong frond that somewhat resembles a feather; it is bilaterally symmetrical, with a central axis supporting a number of lateral branches. The branches appear to be connected to one another by narrow canals. A blunt holdfast attached the animal to the sea floor. Of the three known specimens, the largest is 21 cm tall and reaches 5 cm across; the smaller specimens – presumed to be juveniles – are only a few centimetres long. The frond is flattened, and tapers slightly towards its tip. It consists of about three dozen branches angled at 45º to the central axis, and primarily grew by inflation – perhaps with some addition of branches by apical budding. Unlike modern sea pens, Thaumaptilon’s branches attach to a common base. Lines of pustules on one side of the frond have been interpreted as retracted zooids (individual members of a colonial organism), which are arranged very haphazardly in comparison to the neat combs seen in modern sea pens.

Abundance:

Only three specimens are known.

Maximum Size:
210 mm

Ecology:

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

The holdfast would have anchored the organism to the soft sediment of the sea floor, and could perhaps contract to adjust the height and angle of the frond. Based on the interpretation of the pustules as zooids, a colonial, suspension-feeding lifestyle has been proposed. It has been suggested that Thaumaptilon could retract into its stem when threatened, for protection (Conway Morris, 1998).

References:

ANTCLIFFE, J. B. AND M. D. BRASIER. 2008. Charnia at 50: Developmental models for Ediacaran fronds. Palaeontology, 51(1): 11-26.

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

CONWAY MORRIS, S. 1989. Burgess Shale faunas and the Cambrian explosion. Science, 246(4928): 339.

CONWAY MORRIS, S. 1990. Late Precambrian and Cambrian soft-bodied faunas. Annual Review of Earth and Planetary Sciences, 18(1): 101-122.

CONWAY MORRIS, S. 1993. Ediacaran-like fossils in Cambrian Burgess Shale-type faunas of North America. Palaeontology, 36(3): 593-635.

CONWAY MORRIS, S. 1998. The Crucible of Creation, the Burgess Shale and the Rise of Animals. Oxford University Press, 242 p.

SHU, D. G., S. CONWAY MORRIS, J. HAN, Y. LI, X. L. ZHANG, H. HUA, Z. F. ZHANG, J. N. LIU, J. F. GUO, Y. YAO AND K. YASUI. 2006. Lower Cambrian vendobionts from China and early diploblast evolution. Science, 312(5774): 731-734.

Other Links:

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

Tegopelte gigas

Tegopelte gigas (USNM 189201) – Holotype. Complete specimen showing antennae and appendages partially prepared near the back. Specimen length = 270 mm. Specimen dry – direct (top) and polarized light (bottom). Walcott Quarry.

© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Unranked clade (stem group arthropods)
Species name: Tegopelte gigas
Remarks:

Tegopelte is usually compared to the soft-bodied “trilobites” such as Naraoia and Saperion, but the exact relationships of these taxa to the mineralized trilobites is uncertain (Whittington, 1977). The tegopeltids and other trilobite-like arthropods are sometimes referred to as Trilobitoidea, which when grouped together with the trilobites form the Lamellipedians (Hou and Bergström, 1997; Wills et al., 1998; Edgecombe and Ramsköld, 1999). This group has been variously placed in the upper stem lineage of the arthropods (Budd, 2002), or in the stem lineage of either the mandibulates (Scholtz and Edgecombe, 2006) or the chelicerates (Cotton and Braddy, 2004).

Described by: Simonetta and Delle Cave
Description date: 1975
Etymology:

Tegopelte – from the Greek tegos, “tile,” and pelte, “leather-shield,” referring to the shape of the dorsal body covering.

gigas – from the Greek gigas, “giant,” referring to the large size of the animal.

Type Specimens: Holotype –USNM189201 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: none.

Age & Localities:

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

The Walcott Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Tegopelte was first described by Simonetta and Delle Cave (1975) to include only two relatively large specimens. This original description showed Tegopelte to have a cephalon with six or seven pairs of walking appendages, a thorax of four tergites each bearing five appendages, and a tail segment with ten appendages. Whittington (1985) re-examined the animal, reducing the number of head appendages to three, and describing the thorax as having only three tergites with three appendages each. The tail in Whittington’s (1985) reconstruction had two segments with a total of 20 appendages. Later re-examination by Ramsköld et al. (1996) suggested that the body has no tergites, but instead consists of an undivided dorsal shield. Tegopelte has been grouped together with the Chengjiang taxon Saperion to form the Tegopeltidae (Ramsköld et al., 1996; Hou and Bergström, 1997), a clade later confirmed by cladistic analysis (Edgecombe and Ramsköld, 1999; Hendricks and Lieberman, 2008).

Description:

Morphology:

The dorsal morphology of Tegopelte consists of an elongated oval-shaped dorsal shield that is featureless and undivided. The length of the two known specimens is 25.7 cm and 27.0 cm, making it one of the largest arthropods in the Burgess Shale. The ventral morphology consists of a pair of multi-segmented antennae at the front of the body, followed by a series of identical limbs that are segmented and branch into two (biramous), totaling approximately 33 along the entire body. The biramous limbs have a walking branch made up of six segments with a pair of spines on the terminal segment, and a filamentous branch where numerous elongated oval blades attach to a central shaft. The biramous limbs decrease in size towards the posterior end of the body.

Abundance:

Tegopelte is extremely rare, with only two known specimens.

Maximum Size:
270 mm

Ecology:

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

Tegopelte probably spent much of its time walking on the seafloor, based on the presence of many appendages. It used the segmented branches of its biramous appendages for walking, and it is likely that the filamentous branches were used for oxygen exchange, and to propel the animal through the water during short bursts of swimming. The antennae would have been used to sense the environment. The lack of eyes, gut glands and feeding appendages make it difficult to allocate a feeding strategy to Tegopelte.

References:

BUDD, G. E. 2002. A palaeontological solution to the arthropod head problem. Nature, 417: 271-275.

COTTON, T. J. AND S. J. BRADDY. 2004. The phylogeny of arachnomorph arthropods and the origin of the Chelicerata. Transactions of the Royal Society of Edinburgh: Earth Sciences, 94: 169-193.

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.

EDGECOMBE, G. D. and L. RAMSKÖLD. 1999. Relationships of Cambrian Arachnata and the systematic position of Trilobita. Jounral of Paleontology, 73: 263-287.

HENDRICKS, J. R. AND B. S. LIEBERMAN. 2008. New phylogenetic insights into the Cambrian radiation of arachnomorph arthropods. Journal of Paleontology, 83: 585-594.

HOU, X. AND J. BERGSTRÖM. 1997. Arthropods of the Lower Cambrian Chengjiang fauna, southwest China. Fossils and Strata, 45: 1-116.

RAMSKÖLD, L., J. CHEN, G. D. EDGECOMBE AND G. ZHOU. 1996. Preservational folds simulating tergite junctions in tegopeltid and naraoiid arthropods. Lethaia, 29: 15-20.

SIMONETTA, A. M. AND L. DELLE CAVE. 1975. The Cambrian non-trilobite arthropods from the Burgess shale of British Columbia: A study of their comparative morphology, taxonomy and evolutionary significance. . Palaeontographia Italica, 69: 1-37.

WHITTINGTON, H. B. 1977. The Middle Cambrian trilobite Naraoia, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London, B, 280: 409-443.

WHITTINGTON, H. B. 1985. Tegopelte gigas, a second soft-bodied trilobite from the Burgess Shale, Middle Cambrian, British Columbia. Journal of Paleontology, 59: 1251-1274.

WILLS, M. A., D. E. G. BRIGGS, R. A. FORTEY, M. WILKINSON AND P. H. A. SNEATH. 1998. An arthropod phylogeny based on fossil and recent taxa, p. 33-105. In G. D. Edgecombe (ed.), Arthropod fossils and phylogeny. Columbia University Press, New York.

Other Links:

None

Stephenoscolex argutus

Stephenoscolex argutus (USNM 83936b) – Holotype. Specimen showing the head (top left) followed by the trunk, which is lined by narrow parapodia and setae. Filamentous structures around the body probably represent cyanobacteria. Specimen length = 32 mm. Specimen dry – direct light (left) and wet – direct light (right). Walcott Quarry.

© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Unranked clade (stem group polychaetes)
Species name: Stephenoscolex argutus
Remarks:

Stephenoscolex bears some resemblance to modern polychaetes but cannot be placed in any extant group (Conway Morris, 1979) suggesting a position as a stem-group polychaete (Eibye-Jacobsen, 2004).

Described by: Conway Morris
Description date: 1979
Etymology:

Stephenoscolex – from the Greek scolex, “worm,” and Mount Stephen. Mount Stephen (3,199 m) was named after George Stephen (1829 – 1921), first president of the Canadian Pacific Railway.

argutus – from the Latin argutus, “bright,” in recognition of the shininess of the fossils.

Type Specimens: USNM – 83936b in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. Paratype –ROM32574 in the Royal Ontario Museum, Toronto, ON, 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 Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Walcott (1911; 1931) included the holotype of this species within Canadia dubia, which Simon Conway Morris, in his 1979 re-examination of Burgess Shale polychaetes, reclassified as Stephenoscolex. Conway Morris found a further partial specimen in the ROMcollections, and further specimens have since been recovered by the ROMbelow the Walcott Quarry. However, this additional material awaits detailed study; since the published description rests on two specimens, it must be treated with caution (Eibye-Jacobsen, 2004).

Description:

Morphology:

The worm has a slim body, around 1 mm wide, reaching around 3 cm in length. Its head bears two pairs of appendages extending from its front and sides. It has around forty further segments, each of which bear simple lateral projections (uniramous) called parapodia. The parapodia each bear around fifteen short and simple setae. Cirri and branchiae are absent.

Abundance:

Stephenoscolex was considered one of the rarest annelids from the Burgess Shale but additional material has now been collected from the Walcott Quarry representing 0.28% of the specimens counted in the community (Caron and Jackson, 2008).

Maximum Size:
32 mm

Ecology:

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

There is little that can confidently be stated about the life habit of this animal, but the pattern of spines suggests that it crept or swum over or in the sediment.

References:

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

CONWAY MORRIS, S. 1979. Middle Cambrian polychaetes from the Burgess Shale of British Columbia. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 285(1007): 227-274.

EIBYE-JACOBSEN, D. 2004. A reevaluation of Wiwaxia and the polychaetes of the Burgess Shale. Lethaia, 37(3): 317-335.

WALCOTT, C. D. 1911. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(2): 109-144.

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

Other Links:

None

Skania fragilis

Skania fragilis (ROM 60752) – Part and counterpart (first and second rows). Complete specimen showing antennae. Specimen length = 11 mm. Specimen dry – polarized light (left column) and wet (right column). Raymond Quarry.

© ROYAL ONTARIO MUSEUM. PHOTOS: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Walcott Quarry
Phylum: Walcott Quarry
Higher Taxonomic assignment: Unranked clade (stem group arthropods)
Species name: Skania fragilis
Remarks:

The affinity of Skania is controversial, but most agree it is related to the arthropods. It is similar to Primicaris (Lin et al., 2006; Zhang et al., 2007), and both taxa have been compared to soft-bodied trilobites like Naraoia (Walcott, 1931; Zhang et al., 2007; Hou and Bergström, 1997). Other researchers suggest these taxa are related to the enigmatic Ediacaran taxon Parvancorina (Delle Cave and Simonetta, 1975; Gehling, 1991; Conway Morris, 1993; Simonetta and Insom, 1993), with all three taxa forming a clade in sister group position relative to the trilobites (Lin et al., 2006).

Described by: Walcott
Description date: 1931
Etymology:

Skania – from Skana, the name of a glacier near Mount Robson, British Columbia, Canada.

fragilis – from the Latin fragilis, “brittle,” referring to the delicate nature and small size of the animal.

Type Specimens: Holotype –USNM83950 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: Skania sundbergi Lin et al. 2006 from the Kaili Formation, China.

Age & Localities:

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

The Walcott and Raymond Quarries on Fossil Ridge.

History of Research:

Brief history of research:

Skania fragilis was first described by Walcott (1931) in a posthumous monograph published by his assistant Charles Resser. Resser compared Skania to the trilobites and Naraoia. However in a redescription by Delle Cave and Simonetta (1975), it was suggested instead that Skania was closely related to the Ediacaran taxon Parvancorina minchami Glaessner 1958. This affinity has been much discussed (Gehling, 1991; Conway Morris, 1993; Simonetta and Insom, 1993; Lin et al. 2006), and Skania has also been compared extensively with Primicaris Zhang et al. 2003. Skania and Primicaris have also been interpreted as juveniles (protaspides) of naraoiids (Hou and Bergström, 1997).

Description:

Morphology:

Skania has a single, undifferentiated, soft dorsal shield that is roughly kite-shaped. The dorsal shield is rounded at the front of the head, and tapers towards the posterior of the body, ending in a pair of short margin spines at the posterior end. At the point of maximum width there are sharp genal spines directed posteriorly. The posterior margin of the head is delineated by a narrow rim that is strongly arched forward, with the cephalic region occupying one-quarter of the exoskeletal length. A midgut is preserved in the axial region of the body trunk. Appendages are poorly preserved but consist of a pair of anterior antennae and ten or more paired body limbs.

Abundance:

Skania fragilis is known from fewer than 40 specimens in total.

Maximum Size:
17 mm

Ecology:

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

The ecology of Skania is poorly known because the details of its morphology remain enigmatic. The form of the appendages is assumed to be biramous based on the overall similarity with Primicaris, which possesses biramous appendages, meaning that both animals may have walked on the seafloor, using their filamentous appendages for oxygen exchange and occasional swimming. Skania lacks eyes, so it likely used its antennae to sense the environment. The feeding strategy is unknown.

References:

CONWAY MORRIS, S. 1993. Ediacaran-like fossil in Cambrian Burgess Shale-type faunas of North America. Palaeontology, 36: 593-635.

DELLE CAVE, L. AND A. M. SIMONETTA. 1975. Notes on the morphology and taxonomic position of Aysheaia (Onycophora?) and of Skania (undetermined phylum). Monitore Zoologico Italiano New Series, 9: 67-81.

GEHLING, J. G. 1991. The case for Ediacaran fossil roots to the metazoan tree, p. 181-223. In B. P. Radhakrishna (ed.), The world of Martin F. Glaessner. Geological Society of India, Bangalore.

HOU, X. AND J. BERGSTRÖM. 1997. Arthropods of the Lower Cambrian Chengjiang fauna, southwest China. Fossils and Strata, 45: 1-116.

LIN, J., S. M. GON III, J. G. GEHLING, L. E. BABCOCK, Y. ZHAO, X. ZHANG, S. HU, J. YUAN M. YU AND J. PENG. 2006. A Parvancorina-like arthropod from the Cambrian of South China. Historical Biology, 18: 33-45.

SIMONETTA, A. M. AND E. INSOM. 1993. New animals from the Burgess Shale (Middle Cambrian) and their possible significance for the understanding of the Bilateria. Bolletino di Zoologia, 60: 97-107.

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

ZHANG, X., D. SHU AND D. H. ERWIN. 2007. Cambrian naraoiids (Arthropoda): morphology, ontogeny, systematics, and evolutionary relationships. Palaeontological Society Memoir, 68: 1-52.

Other Links:

None