The Burgess Shale

Stephenospongia magnipora

Stephenospongia magnipora (ROM 43127) – Holotype. Fragment of the only known specimen of the species showing large holes in the wall of this sponge. Specimen height = 44 mm. Specimen dry – polarized light. Trilobite Beds on Mount Stephen.

© ROYAL ONTARIO MUSEUM. PHOTO: JEAN-BERNARD CARON

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Hexactinellida (Order: Reticulosa)
Species name: Stephenospongia magnipora
Remarks:

Stephenospongia is placed in the Family Hintzespongiidae (primitive hexactinellids). Hexactinellid sponges (glass sponges) have a skeleton composed of four to six-pointed spicules. They are considered to be an early branch within the Porifera phylum due to their distinctive composition.

Described by: Rigby
Description date: 1986
Etymology:

Stephenospongia – from Mount Stephen (3,199 m), a mountain peak in Yoho National Park, named after George Stephen (1829 – 1921), first president of the Canadian Pacific Railway and the Latin spongia, meaning “sponge.”

magnipora – from the Latin magnus, “great,” and porus, “pore.” The name makes reference to the large pores present in the skeleton of this sponge.

Type Specimens: Holotype –ROM43127 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:

Stephenospongia was described by Rigby (1986) (see also Rigby and Collins 2004) based on a single specimen discovered by the Royal Ontario Museum in 1982.

Description:

Morphology:

Stephenospongia has a conical and almost cylindrical shape. The skeleton is composed of six rayed spicules (called hexactines) typical of the hexactinellid sponges. The spicules mesh together to form a single layer and are arranged in an irregular fashion especially around holes in the sponge wall. Prominent holes organized in vertical and horizontal rows are separated by tracts of spicules with ray lengths reaching more than one centimetre. The basal and top parts are not preserved.

Abundance:

Only a single specimen is known and comes from the Trilobite Beds.

Maximum Size:
44 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Stephenospongia 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:

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.

Other Links:

None

Sphenothallus sp.

Taxonomy:

Sphenothallus sp. (GSC 134789). Fragment of a large specimen showing longitudinal thickenings clearly differentiated near the aperture area (to the right). A Micromitra (Dictyonina) brachiopod is attached to the lower part of the tube. Approximate specimen length = 50 mm. Specimen dry – direct light. Trilobite Beds on Mount Stephen.

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

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Unranked clade (stem group cnidarians)
Species name: Sphenothallus sp.
Remarks:

Sphenothallus has been compared to some form of tubiculous annelid worm or 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: Van Iten et al.
Description date: 2002
Etymology:

Sphenothallus – from the Greek sphen, “wedge”, and thallos, “branch.”

Species name not determined.

Type Specimens: Not applicable
Other species:

Burgess Shale and vicinity: Many shared similarities suggest that other thecate Burgess Shale fossils such as Byronia annulataCambrorhytium majorCfragilis and Tubulella flagellum, may be related to Sphenothallus sp.

Other deposits: Other species occur worldwide in rocks from the Cambrian to the Silurian periods. Sphenothallus is also known in the Kaili Formation (Zhu et al., 2000).

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:

Two specimens from the Trilobite Beds were illustrated in 2002 (Van Iten et al.). A third previously unrecognized specimen was identified in the Geological Survey of Canada collections in Ottawa (Billings collection) in the Spring of 2010. Owing to the relatively low degree of morphological variations among all known species, it is not currently possible to assign the Burgess Shale form to any particular species without better preserved specimens.

Description:

Morphology:

The chitinophosphatic tube (theca) of Sphenothallus consists of longitudinal thickenings which are particularly obvious towards the aperture area. The tube is gently curved and does not seem to branch. The maximum diameter of the largest specimen is about 4 mm for a length of about 75 mm. A thin wall is present between the longitudinal thickenings and terminates in a smooth margin near the aperture, a couple of millimeters beyond the longitudinal thickenings. The tube is roughly circular in the apical region and is very slender, with the two longitudinal thickenings less differentiated in this area. The surface of the entire tube including thickenings is smooth with no evidence of ridges or annulations. All three specimens lack the apical ends, so it is not evident that this species had a holdfast and there is no evidence of soft-tissue preservation.

Abundance:

Only three specimens known from the Trilobite Beds on Mount Stephen.

Maximum Size:
75 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

The theca of Sphenothallus was likely attached to the substrate via an apical disc as can be seen in other better known species. The absence of soft tissue preservation makes the assignment to a particular feeding strategy tentative. By comparison with possible related forms such as Cambrorhytium, a carnivorous or suspension feeding habit seems possible.

References:

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

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.

Other Links:

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Scolecofurca rara

Scolecofurca rara (GSC 45331) – Holotype (part and counterpart). Only known specimen of the species showing the pair tentacles in direct light (anterior to the right). Specimen length = 65 mm. Specimen wet – direct light (top), dry – polarized light (middle and bottom). Raymond Quarry.

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

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Unranked clade (stem group priapulids)
Species name: Scolecofurca rara
Remarks:

Scolecofurca belongs to the priapulid worm stem group (Harvey et al., 2010; Wills, 1998).

Described by: Conway Morris
Description date: 1977
Etymology:

Scolecofurca – from the Greek skolex, meaning “worm,” and the Latin furca, “fork,” in reference to the fork-like anterior of this worm.

rara – from the Latin rarus, “infrequent,” in reference to the rarity of the species.

Type Specimens: Holotype – GSC45331 in the Geological Survey of Canada, Ottawa, 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 Raymond Quarry on Fossil Ridge.

History of Research:

Brief history of research:

This worm was described by Conway Morris in 1977 as a possible primitive priapulid. Later analyses showed that S. rara belongs to the priapulid stem group (Harvey et al., 2010; Wills, 1998).

Description:

Morphology:

Scolecofurca is known from a single incomplete specimen, which is estimated to have reached nine centimeters in total length. Like other priapulids, the body is divided into a proboscis and a trunk. The proboscis is fringed with small extensions called papillae, and tipped with a pair of conspicuous tentacles giving the appearance of a two-pronged fork. The trunk is annulated and the gut appears to be represented by a simple tube. Contrary to all the other species of priapulids from the Burgess Shale, this form does not have spines or hooks on the proboscis or body.

Abundance:

This species is known from a single specimen.

Maximum Size:
90 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

The general body-shape and presence of a proboscis suggests Scolecofurca was a burrower. The tentacles might have had a sensory function rather than being used for prey manipulation, but the mode of feeding of this species is unknown.

References:

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

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

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

Other Links:

None

Protoprisma annulata

Protoprisma annulata (ROM 53557) – Holotype. Nearly complete specimen showing a clump of branches attached to a basal part (coated with ammonium chloride sublimate to show details). Specimen height = 150 mm. Specimen dry – direct light. Tulip Beds (S7) on Mount Stephen.

© Royal Ontario Museum. Photo: Jean-Bernard Caron

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Hexactinellida (Order: Reticulosa)
Species name: Protoprisma annulata
Remarks:

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: Rigby and Collins
Description date: 2004
Etymology:

Protoprisma – from the Greek protos, “first,” and prisma, “prism.” This name refers to the early occurrence of this prismatic sponge.

annulata – from the Latin annulatus, meaning “ringed, or circular.” The name makes reference to the annulated growth form of this species.

Type Specimens: Holotype –ROM53557, 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 Tulip Beds (S7) on Mount Stephen and the Raymond Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Ribgy and Collins described this genus in 2004 based on material collected by the Royal Ontario Museum.

Description:

Morphology:

This sponge has an elongate annulated shape with several branches, which give it a hand-like appearance. Each branch has vertical angular ridges which results in a prismatic cross section. The ridges and the troughs between them are composed of fine hexactine spicules, cross-connected by horizontal strands that thatch the skeleton together. The type specimen is almost complete at 15 cm tall and shows that all of the branches originate from a central point at the base. The base of the sponge would have had an attachment structure to keep the sponge anchored in the sediment surface. As neither of the two specimens recovered are complete, it is not known what the top of this sponge would have looked like.

Abundance:

Protoprisma is known only from two specimens, one collected from the Tulip Bed (S7) locality on Mount Stephen and one from the Raymond Quarry on Fossil Ridge.

Maximum Size:
150 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Protoprisma 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:

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

Insolicorypha psygma

Insolicorypha psygma (USNM 198712) – Holotype, part and counterpart. Only known specimen showing the purported head (top) surrounded by a dark stain (probably representing decay fluids), setae, and gut trace. Specimen length = 12 mm. Specimen dry – polarized light (both images). Walcott Quarry.

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

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Unranked clade (stem group polychaetes)
Species name: Insolicorypha psygma
Remarks:

The single specimen (perhaps incomplete, Eibye-Jacobsen, 2004) of this species is too poorly known to allow detailed studies of its affinities.

Described by: Conway Morris
Description date: 1979
Etymology:

Insolicorypha – from the Latin insolitus, “unusual,” and the Greek koryphe, “head,” thus, “unusual head.”

psygma – from the Greek psygma, “fan,” in reference to the fan-like arrangement of the worm’s bristles.

Type Specimens: Holotype –USNM198667 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:

Only a single specimen is known. This was originally interpreted by Conway Morris (1979) as a complete animal with an abnormal head. Eibye-Jacobsen (2004) later suggested that the specimen represented just the rear part of the animal, and that the ragged edge of the torn body wall formed the illusion of a head.

Description:

Morphology:

This tiny worm (12 mm long) had at least 19 segments, each bearing a pair of lateral projections called parapodia. On the first and perhaps second segment the parapodia are simple (uniramous), while all the other segments have biramous parapodia (divided into two sections of unequal lengths). In the third segment through to the last segment, parapodia support two main bundles of setae, the notosetae (on the upper branch) and the neurosetae (on the lower branch). The notosetae are short while the neurosetae are much longer. The branch bearing the neurosetae has three (two dorsal) and one ventral cirri (representing sensory of secretory organs) and is much longer. The purported front end of the animal has an elongate projection (prostomium) divided into two main sections.

Abundance:

Only a single specimen of Insolicorypha is known and comes from the Walcott Quarry.

Maximum Size:
12 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Insolicorypha probably had a similar mode of life to modern swimming annelids which also have sensory cirri, but the rarity of this species makes it impossible to conclude exactly how the animal fed. The fans of bristles are clear adaptations to swimming, which may contribute to the organism’s rarity in the Burgess Shale, which primarily preserves bottom-dwelling species.

References:

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: 227-274.

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

Other Links:

None

Hanburia gloriosa

Hanburia gloriosa (ROM 48468). Complete individual (external mold). Specimen length = 26 mm Specimen coated with ammonium chloride sublimate to show details. Trilobite Beds on Mount Stephen.

© Royal Ontario Museum. Photo: Jean-Bernard Caron

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Trilobita (Order: Corynexochida?)
Species name: Hanburia gloriosa
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:

Hanburia – unspecified, but probably after Hanbury Peak or Hanbury Glacier in the Canadian Rockies, in turn named for David T. Hanbury (1864-1910), a British explorer of the Canadian Northwest Territories.

gloriosa – from the Latin gloriosus, meaning “glorious” or “boastful,” perhaps in allusion to the unusual cephalic morphology of this rare species.

Type Specimens: Lectotype –USNM61724, 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, Glossopleura to Bathyuriscus-Elrathina Zones (approximately 505 million years ago).
Principal localities:

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

History of Research:

Brief history of research:

Walcott’s three original specimens of Hanburia gloriosa were found over the course of five years of quarrying the Phyllopod Bed on Fossil Ridge (Walcott, 1916); two more from this locality are also in theUSNMcollections. A singleUSNMspecimen was later found by Charles Resser, supposedly from the “Ogygopsis shale” on Mount Stephen (Rasetti, 1951), but this is almost certainly an error. Harry Whittington reassessed this odd trilobite in 1998.

Description:

Morphology:

Hard parts: the few known specimens of Hanburia gloriosa range in length from 4 mm (for a juvenile stage) to 35 mm. Dorsal shields are broadly ovate to subcircular in outline and all specimens are considerably flattened by compression of the thin exoskeleton. The cephalon is semicircular with a weak, shallow border furrow along the posterior and lateral margins, fading out towards the anterior corners of the glabella. The glabella in small specimens expands forwards and shows two pairs of faint bulbous lateral lobes; in larger specimens, the glabella is parallel-sided and the lobes are subdued. There are no apparent eyes located laterally on the cephalon, and there is no sign of dorsal facial suture. In these two features, Hanburia is unique among the non-agnostoid trilobites of the Burgess Shale.

Whittington (1998) has suggested that the facial suture might run along the outside edge of the cephalon, or ventrally, crossing to the dorsal side only at the genal angles, which in all specimens appear to be rounded. Larger individuals show six or seven segments in the comparatively short thorax, and a single known (presumed) juvenile stage shows four; the distal tips of the pleurae are rounded. The semicircular pygidium lacks a defined border, and is approximately the same width and length as the cephalon. Seven or eight axial rings and a terminal piece make up the pygidial axis, which ends short of the posterior margin. Eight or nine pairs of well-marked pygidial pleurae radiate out and back from the axis.

Unmineralized anatomy: not known

Abundance:

Very rare in all the Burgess Shale localities.

Maximum Size:
35 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Due to its unusual cephalic morphology (i.e., no dorsal sutures or lateral compound eyes), rarity, and unique occurrence only in the Burgess Shale, Hanburia gloriosa remains an ecological enigma. Other “blind” Cambrian trilobites with somewhat similar morphologies have been interpreted as inhabiting deeper waters, perhaps below the photic zone (Whittington, 1998).

References:

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

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. Smithsonian Miscellaneous Collections, 64(3): 157-258.

WHITTINGTON, H. B. 1998. Hanburia gloriosa: rare trilobite from the Middle Cambrian, Stephen Formation, British Columbia, Canada. Journal of Paleontology, 72: 673-677.

Other Links:

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Hamptoniella foliata

Hamptoniella foliata (ROM 43816) – Holotype. Complete specimen. Specimen height = 20 mm. Specimen dry – direct light (left), wet – polarized light (right). Trilobite Beds on Mount Stephen.

© Royal Ontario Museum. Photos: Jean-Bernard Caron

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Demospongea (Order: Monaxonida)
Species name: Hamptoniella foliata
Remarks:

Hamptoniella is a primitive demosponge, with a type of skeleton considered transitional between Hamptonia and Hazelia (Rigby, 1986). Demosponges, the same group that are harvested as bath sponges, represent the largest class of sponges today.

Described by: Rigby
Description date: 2004
Etymology:

Hamptoniella – unspecified; possibly from the town of Hampton in Virginia (see Hamptonia). The Latin suffix, ella is added to Hampton to form a diminutive.

foliata – from the Latin folia, “leaf,” in reference to the leaf like aspect of the sponge.

Type Specimens: Holotypes –ROM43816 (H. foliata wrongly referencedROM48816 in Rigby and Collins, 2004) andROM44285 (H. hirsuta) in the Royal Ontario Museum, Toronto, Canada.
Other species:

Burgess Shale and vicinity: H. hirsuta Rigby and Collins, 2004 from the Trilobite Beds on Mount Stephen.

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 sponge was described by Rigby and Collins (2004) based on new material collected by the Royal Ontario Museum.

Description:

Morphology:

Hamptoniella foliata is a relatively small sponge, with its body shape varying from funnel-shaped to turbinate. The skeleton is composed of simple and straight spicules that are pointed at both ends (oxeas). The axial zone of the sponge does not have a central cavity (spongocoel) and there is no large opening (osculum). Instead a number of subvertical and relatively large canals are present in the axial area. Smaller sized canals diverge from the larger canals towards the sides and the top of the sponge. Spicules tend to be clustered and parallels to canals. H. hirsuta differs from H. foliata, by appearing more spinose.

Abundance:

H. foliata has been described based on 3 specimens and H. hirsuta based on a single specimen.

Maximum Size:
24 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Hamptoniella 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:

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

Halichondrites elissa

Halichondrites elissa (ROM 53575) – Part and counterpart. Nearly complete individual showing the pointed root tuft. Specimen height = 140 mm. Specimen dry – direct light (left), wet – direct light (right). Walcott Quarry.

© Royal Ontario Museum. Photos: Jean-Bernard Caron

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Demospongea (Order: Monaxonida)
Species name: Halichondrites elissa
Remarks:

Halichondrites 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:

Halichondrities – from the Greek hal, meaning “belonging to the sea,” chon, meaning “funnel” or “tube,” and dri, meaning “thicket.” The name refers to the shape of this marine sponge with a thicket of long hair-like spicules.

elissa – from the Greek eliss, meaning “to roll, or to turn about.” This name may refer to the spiral pattern of the small spicules of this sponge.

Type Specimens: Holotype –USNM66447 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: An unidentified species, Halichondrites sp. from Mount Stephen (Rigby and Collins, 2004).

Other deposits: H. confusus Dawson, 1889 from the Ordovician of Quebec at Little Métis.

Age & Localities:

Age:
Lower Cambrian, Wutingaspis-Eoredlichia Zone to Middle Cambrian, Bathyuriscus-Elrathina Zone (approximately 510 to 505 million years ago).
Principal localities:

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

Other deposits: H. elissa from the Lower Cambrian Chengjiang fauna (Chen et al., 1997; Luo et al., 1999).

History of Research:

Brief history of research:

Walcott assigned this species to the genus Halichondrites in 1920. Ribgy (1986) re-described this genus and hypothesized that Halichondrites probably evolved from an early species of Leptomitus and established a new family called Halichondritidae to include this genus. New specimens collected by the Royal Ontario Museum were subsequently described by Rigby and Collins in 2004.

Description:

Morphology:

This sponge has a cone shaped base that extends upwards to form a long tube. The walls of the sponge are smooth with a thatch of small spicules that are vertically arranged in a clockwise spiraling pattern. There are no canals visible in the wall; they may be very small or run parallel to the wall. The most distinctive part of this sponge is the long thick, densely arranged spicules that emerge from the wall. These spicules are orientated upwards and may be up to 8.5 cm long. This sponge can be over 20 cm tall and is one of the tallest and most hirsute (densely covered in hair) of the Burgess Shale sponges. Water would have entered though small pores in the wall, moving into the central cavity and out the circular osculum at the top of the sponge.

Abundance:

Halichondrites is very rare and represents only 0.01% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
215 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Halichondrites 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.

CHEN, J. Y., Y. N. CHENG AND H. V. ITEN. 1997. The Cambrian explosion and the fossil record. National Museum of Natural Science Taiwan, Taichung, 319 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: 105 p.

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

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

Other Links:

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Portalia mira

Portalia mira (USNM 83927) – Holotype, part and counterpart. Complete specimen preserved with Mackenzia costalis. Anterior possible to the right. Specimen length = 100 mm. Specimen dry – polarized light. Walcott Quarry.

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

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Non applicable
Species name: Portalia mira
Remarks:

Portalia is regarded as a problematic organism awaiting a full redescription (Briggs and Conway Morris, 1986).

Described by: Walcott
Description date: 1918
Etymology:

Portalia – from Portal Peak (2,911 m), north of the Burgess Shale in Banff National Park.

mira – from the Latin mirus, “wonderful,” in reference to the morphology of the animal.

Type Specimens: Holotype –USNM83927 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:

The only known specimen of Portalia was first illustrated by Walcott in a brief communication published in 1918 and refigured in a posthumous publication (Walcott, 1931). Walcott interpreted this fossil as a holothurian, a member of a group of echinoderms better known as sea-cucumbers. Madsen (1957) suggested Portalia might be a primitive sponge, but Durham (1974) thought that the holothurian affinity could not be rejected without further studies (see also Conway Morris, 1979). The relationships of Portalia remain difficult to establish (Briggs and Conway Morris, 1986).

Description:

Morphology:

The body of Portalia is sausage-shaped and the most distinctive features are a series of elongate tentacle-like structures covering the entire surface. These structures tend to split into several simple branches. A central strand within the body has been interpreted as part of the gut and the head has been tentatively identified as a darker indistinct area at one end.

Abundance:

Portalia is known from a single specimen.

Maximum Size:
100 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Not enough is known about this organism to interpret its feeding strategy.

References:

BRIGGS, D. E. G. AND S. CONWAY MORRIS. 1986. Problematica from the Middle Cambrian Burgess Shale of British Columbia, p. 167-183. In A. Hoffman and M. H. Nitecki (eds.), Problematic fossil taxa (Oxford Monographs on Geology and Geophysics No. 5). Oxford University Press & Clarendon Press, New York.

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

MADSEN, F. J. 1957. On Walcott’s supposed Cambrian holothurians. Journal of Paleontology, 31(1): 281-286.

WALCOTT, C. 1918. Geological explorations in the Canadian Rockies. From “Explorations and Field-Work of the Smithsonian Institution in 1917”. Smithsonian Miscellaneous Collections, 68: 4-20.

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

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Habelia? brevicauda

Habelia? brevicauda (USNM 144910) – Holotype. Complete individual preserved without appendages. Total specimen length = 50 mm. Specimen dry – polarized light. Walcott Quarry.

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

Taxonomy:

Kingdom: Extremely rare
Phylum: Extremely rare
Higher Taxonomic assignment: Unranked clade (stem group arthropods)
Species name: Habelia? brevicauda
Affinity:

Habelia? brevicauda is too poorly known to definitively determine its affinities. It has been aligned in some studies with the arachnomorphs (a group including chelicerates and trilobites), and has been suggested to be closely related to lamellipedians such as Naraoia and the trilobites (Briggs and Fortey, 1989), or placed within Megacheira as a close relative of Leanchoilia (Wills et al., 1998).

Described by: Simonetta
Description date: 1964
Etymology:

Habelia – from Mount Habel (3,161 m), today known as Mount Des Poilus, at the head of Yoho Valley, named in 1900 by Norman Collie in honour of Jean Habel, a German mountaineer. The name Mount Habel is now applied to a peak north of Mount Des Poilus.

brevicauda – from the Latin brevis, “short,” and cauda, “tail.”

Type Specimens: Holotype –USNM144910 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: Habelia optata from Walcott Quarry, Fossil Ridge and The Monarch in Kootenay National Park.

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.

History of Research:

Brief history of research:

Habelia optata was first described by Walcott in 1912, to which Simonetta added the possible second species Habelia? brevicauda in 1964. This second species was later restudied by Whittington (1981). Phylogenetic analyses suggest a position within the arachnomorphs (Briggs and Fortey, 1989; Wills et al., 1998). If this is confirmed, Habelia probably represent a stem group of the Mandibulata, which includes crustaceans, myriapods, and hexapods (Scholtz and Edgecombe, 2006).

Description:

Morphology:

The body ranges in size from 1.8 – 5.4 cm and consists of a half-circle head shield and a trunk with twelve segments, the last of which bears a posterior spine. The head shield is smooth and featureless. The trunk segments have a broad, convex axial region, with blade-shaped elements (pleura) extending from either side. The pleura are short and round at the anterior of the body, but become progressively wider and have increasingly backward-pointing tips towards the posterior. The short, broad posterior spine tapers with a bluntly rounded tip.

In the type species, Habelia optata, the exoskeleton is covered in small tubercules , and appendages include a pair of antennae, two pairs of head appendages that are segmented and branch into two (biramous), and six pairs of possibly gnathobasic biramous trunk appendages (i.e., with a robust and spiny basal podomere or segment used for crushing food items). Tubercules and appendages have not been described in Habelia? brevicauda, which is why its placement in the genus is uncertain.

Abundance:

Habelia? brevicauda was originally described from fewer than ten specimens.

Maximum Size:
54 mm

Ecology:

Life habits: Extremely rare
Feeding strategies: Extremely rare
Ecological Interpretations:

Habelia? brevicauda is assumed to have walked on trunk limbs, using its head appendages to manipulate food items. If gnathobases were present, they may have served to masticate food. The frontal antennae were presumably sensory. Considerable flexure of the head may have been possible, which may have allowed Habelia to use its cephalon to dig into the sediment in search of food. It walked along the sea floor while digging and scavenging food items.

References:

BRIGGS, D. E. G. AND R. A. FORTEY. 1989. The early radiation and relationships of the major arthropod groups. Science, 246: 241-243.

ELLIOTT, D. K. AND D. L. MARTIN. 1987. A new trace fossil from the Cambrian Bright Angel Shale, Grand Canyon, Arizona. Journal of Paleontology, 61: 641-648.

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.

SIMONETTA, A. M. 1964. Osservazioni sugli artropodi non trilobiti della ‘Burgess Shale’ (Cambriano medio). III conributo. Monitore Zoologico Italiano, 72: 215-231.

WALCOTT, C. D. 1912. Middle Cambrian Branchiopoda, Malacostraca, Trilobita and Merostomata. Smithsonian Miscellaneous Collections, 57: 145-228.

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.

WHITTINGTON, H. B. 1981. Rare arthropods from the Burgess Shale, Middle Cambrian, British Columbia. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences, 292: 329-357.

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