The Burgess Shale

Haplophrentis carinatus

3D animation of Haplophrentis carinatus.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Class: Hyolitha (Order: Hyolithida, stem group molluscs)
Remarks:

Haplophrentis belongs to a group of enigmatic cone-shaped to tubular fossils called hyoliths that are known only from the Palaeozoic. Their taxonomic position is uncertain, but the Hyolitha have been regarded as a separate phylum, an extinct Class within Mollusca (Malinky and Yochelson, 2007), or as stem-group molluscs.

Species name: Haplophrentis carinatus
Described by: Matthew
Description date: 1899
Etymology:

Haplophrentis – from the Greek haploos, “single,” and phrentikos, “wall,” in reference to the single wall within the shell.

carinatus – from the Latin carinatus, “keel-shaped,” referring to the morphological similarity to the bottom of a boat.

Type Specimens: Lectotype –ROM8463a in the Royal Ontario Museum, Toronto, Canada.
Other species:

Burgess Shale and vicinity: none

Other deposits: H. reesei Babcock & Robinson, 1988 (type species), from the lower Middle Cambrian Spence Shale and elsewhere in Utah; H.? cf. carinatus from the Middle Cambrian Kaili deposit in China (Chen et al., 2003).

Age & Localities:

Period:
Middle Cambrian, Albertella Zone to 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 Stanley Glacier in Kootenay National Park.

History of Research:

Brief history of research:

Matthew described Hyolithes carinatus from the Trilobite Beds in 1899 based on five incomplete specimens. Babcock and Robison (1988) reviewed the original fossils, along with additional specimens collected by the Royal Ontario Museum from various Burgess Shale localities. They concluded that the species carinatus didn’t belong in Hyolithes, and established a new genus, Haplophrentis, to accommodate it.

Description:

Morphology:

Like all hyoliths, Haplophrentis had a weakly-mineralized skeleton that grew by accretion, consisting of a conical living shell (conch), capped with a clam-like “lid” (operculum), with two slender, curved and rigid structures known as “helens” protruding from the shell’s opening. The function of these helens is still debated, but one possibility was to allow settlement and stabilization on the sea floor. Haplophrentis had a wiggly gut whose preserved contents are similar to the surrounding mud.

H. carinatus usually grew to around 25 mm in length, although some specimens reached as much as 40 mm; the species is distinguished from H. reesei, its cousin from Utah, by the faint grooves on its upper surface, the more pronounced net-like pattern on its “lid” (operculum), and its wider, more broadly-angled living shell (conch).

Haplophrentis can be distinguished from the similar hyolith genus Hyolithes because it bears a longitudinal wall running down the inner surface of the top of its living-shell.

Abundance:

Haplophrentis is relatively common on Fossil Ridge and in the Walcott Quarry in particular, accounting for 0.35% of the community there (Caron and Jackson, 2008).

Maximum Size:
40 mm

Ecology:

Ecological Interpretations:

Haplophrentis probably moved very little; its helens appear unsuited for use in locomotion (See Butterfield and Nicholas, 1996; Martí Mus and Bergström, 2005; Runnegar et al., 1975). Whilst Haplophrentis feeding mode remains somewhat conjectural, it probably consumed small organic particles from the seafloor. Numerous specimens have been found in aggregates or in the gut of the priapulid worm Ottoia prolifica suggesting Haplophrentis was actively preyed upon and ingested (Conway Morris, 1977; Babcock and Robison, 1988).

References:

BABCOCK, L. E. AND R. A. ROBISON. 1988. Taxonomy and paleobiology of some Middle Cambrian Scenella (Cnidaria) and hyolithids (Mollusca) from western North America. University of Kansas Paleontological Contributions, Paper, 121: 1-22.

BUTTERFIELD, N. J. AND C. NICHOLAS. 1996. Burgess Shale-type preservation of both non-mineralizing and “shelly” Cambrian organisms from the Mackenzie Mountains, Northwestern Canada. Journal of Paleontology, 70: 893-899.

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

CHEN, X. Y. ZHAO AND P. WANG. 2003. Preliminary research on hyolithids from the Kaili Biota, Guizhou. Acta Micropalaeontologica Sinica, 20: 296-302.

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

MALINKY, J. M. AND E. L. YOCHELSON. 2007. On the systematic position of the Hyolitha (Kingdom Animalia). Memoir of the Association of Australasian Palaeontologists, 34: 521-536.

MARTÍ MUS, M. AND J. BERGSTRÖM. 2005. The morphology of hyolithids and its functional implications. Palaeontology, 48:1139-1167.

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.

RUNNEGAR, B., J. POJETA, N. J. MORRIS, J. D. TAYLOR, M. E. TAYLOR AND G. MCCLUNG. 1975. Biology of the Hyolitha. Lethaia, 8: 181-191.

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Pirania muricata

3D animation of Pirania muricata and other sponges (Choia ridleyi, Diagoniella cyathiformis, Eiffelia globosa, Hazelia conferta, 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:

Class: Demospongea (Order: Monaxonida)
Remarks:

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

Species name: Pirania muricata
Described by: Walcott
Description date: 1920
Etymology:

Pirania – from Mount Saint Piran (2,649 m), situated in the Bow River Valley in Banff National Park, Alberta. Samuel Allen named Mount St. Piran after the Patron Saint of Cornwall in 1894.

muricata – from the Latin muricatus, “pointed, or full of sharp points.” The name refers to the large pointed spicules extending out from the wall of the sponge.

Type Specimens: Lectotype –USNM66495 (erroneously referred as 66496 in Rigby, 1986), in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none

Other deposits: Pirania auraeum Botting, 2007 from the Lower Ordovician of Morocco (Botting, 2007); Pirania llanfawrensis Botting, 2004 from the Upper Ordovician of England (Botting, 2004).

Age & Localities:

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

The Walcott Quarry on Fossil Ridge. The Trilobite Beds and Tulip Beds (S7) on Mount Stephen and several smaller sites on Mount Field, Mount Stephen and Mount Odaray.

History of Research:

Brief history of research:

Pirania was first described by Walcott (1920). Rigby (1986) redescribed this sponge and concluded that the skeleton is composed of hexagonally arranged canals, large pointed spicules and tufts of small spicules. This sponge was also reviewed by Rigby and Collins based on new material collected by the Royal Ontario Museum (2004).

Description:

Morphology:

Pirania is a thick-walled cylindrical sponge that can have up to four branches. The skeleton of the sponge is composed of tufts of small spicules and has very distinctive long pointed spicules that emerge from the external wall. Long canals perforate the wall of the sponge to allow water flow through it. Branching occurs close to the base of the sponge.

Abundance:

Pirania is common in most Burgess Shale sites but comprises only 0.38% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
30 mm

Ecology:

Ecological Interpretations:

Pirania 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. The brachiopods Nisusia and Micromitra a range of other sponges and even juvenile chancelloriids are often found attached to the long spicules of this sponge, possibly to avoid higher turbidity levels near the seafloor.

References:

BOTTING, J. P. 2004. An exceptional Caradoc sponge fauna from the Llanfawr Quarries, Central Wales and phylogenetic implications. Journal of Systematic Paleontology, 2: 31-63.

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.

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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Eldonia ludwigi

3D animation of Eldonia ludwigi.

Animation by Phlesch Bubble © Royal Ontario Museum

Taxonomy:

Class: Unranked clade Cambroernida (stem group ambulacrarians)
Remarks:

Eldonia, together with other discoidal or pedunculate fossils such as Herpetogaster, probably belongs in the stem group to a clade known as the Ambulacraria, represented by both echinoderms and hemichordates (Caron et al., 2010).

Species name: Eldonia ludwigi
Described by: Walcott
Description date: 1911
Etymology:

Eldonia – from Eldon, a train stop on the Canadian Pacific Railway 30 km east of Field. Eldon is named after a town in County Durham, England, and means “Aelle’s hill.”

ludwigi – after Hubert Ludwig, a German echinoderm expert who described many fossil holothurians.

Type Specimens: Lectotype –USNM57540 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: Stellostomites eumorphus (Sun and Hou, 1987), from the Lower Cambrian Chengjiang fauna, was redescribed as Eldonia eumorpha (Chen et al., 1995). However, S. eumorphus is retained in the literature as the only valid species (Zhu et al. 2002); E. berbera was described from the Upper Ordovician of Morocco (Alessandrello and Bracchi, 2003). If confirmed it would be the youngest stratigraphic occurrence for the genus.

Age & Localities:

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

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

Other deposits: Middle Cambrian Spence Shale and Marjum Formation in Utah (Conway Morris and Robison, 1988).

History of Research:

Brief history of research:

Described by Walcott in 1911, Eldonia was originally interpreted as a holothurian (sea cucumber within the echinoderms), a view that was accepted by some eminent experts at the time (Clark A.H., 1913) and upheld by later re-examination of the material (Durham, 1974). However, this interpretation has always had detractors (Clark H.L., 1912; Dzik, 1991, 1997; Madsen, 1956, 1957, 1962; Paul and Smith, 1984), and the lack of key echinoderm features prohibits a close relationship with that group (Conway Morris, 1993; see also Zhu et al., 2002). Despite their resemblance to jellyfish (scyphozoans) there is a wide consensus that eldoniids do not share any affinities with cnidarians. A connection to “lophophorates” (e.g., brachiopods, phoronids) has been argued in more detail (Chen et al., 1995, Dzik, 1997), but this status remains rather problematic. The description of Eldonia’s close relative Herpetogaster provides a possible link to the Ambulacraria, a group that contains the echinoderms and hemichordates (Caron and Conway Morris, 2010).

Fragments of the reflective gut have been extracted by acid maceration and analyzed for taphonomic studies (Butterfield, 1990).

Description:

Morphology:

Eldonia has a discoidal body with both anus and mouth opening ventrally. Fine rays radiate from a central point within the disc. The gut coils clockwise (viewed from the dorsal surface) around the centre of the organism and is clearly separated into a pharynx, stomach (the darker area), and narrow intestine. There is a pair of relatively stout tentacles around the mouth which probably were used for feeding.

Abundance:

Walcott collected hundreds of specimens of Eldonia in a single fossil layer within the Phyllopod Bed that he called the Great Eldonia Layer. Additional specimens have since been collected from the Walcott Quarry, where they comprise 0.4% of the community (Caron and Jackson, 2008).

Maximum Size:
150 mm

Ecology:

Ecological Interpretations:

Eldonia has conventionally been interpreted as a free-floating filter-feeder. However, based on its morphology, preservational patterns, and its similarity with Herpetogaster, a benthic lifestyle has also been proposed, with its tentacles either collecting food from the water, or sweeping the sea floor for particles of detritus (Caron and Conway Morris, 2010). It is unclear whether the animal could move at least occasionally or was permanently stationary (sessile).

References:

ALESSANDRELLO, A. AND G. BRACCHI. 2003. Eldonia berbera n. sp. a new species of the enigmatic genus Eldonia Walcott, 1911 from the Rawtheyan (Upper Ordovician) of Anti-Atlas (Erfoud, Tafilalt, Morocco). Atti della Società italiana di scienze naturali e del Museo civico di storia naturale in Milano, 144(2): 337-358.

BUTTERFIELD, N. J. 1990. Organic preservation of non-mineralizing organisms and the taphonomy of the Burgess Shale. Paleobiology, 16(3): 272-286.

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

CARON, J.-B., S. CONWAY MORRIS AND D. SHU. 2010. Tentaculate fossils from the Cambrian of Canada (British Columbia) and China (Yunnan) interpreted as primitive deuterostomes. PLoS ONE, 5(3): e9586.

CHEN, J.-Y., M.-Y. ZHU AND G.-Q. ZHOU. 1995. The early Cambrian medusiform metazoan Eldonia from the Chengjiang Lagerstätte. Acta Palaeontologica Polonica, 40: 213-244.

CLARK, H. L. 1912. Fossil holothurians. Science, 35(894): 274-278.

CLARK, A. H. 1913. Cambrian holothurians. American Naturalist, 48: 488-507.

CONWAY MORRIS, S. AND R. A. ROBISON. 1988. More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia. The University of Kansas Paleontological Contributions, 122: 23-84.

CONWAY MORRIS, S. 1993. The fossil record and the early evolution of the Metazoa. Nature, 361(6409): 219-225.

DURHAM, J. W. 1974. Systematic Position of Eldonia ludwigi Walcott. Journal of Paleontology, 48(4): 751-755.

DZIK, J. 1991. Is fossil evidence consistent with traditional views of the early metazoan phylogeny?, p. 47-56. In A. M. Simonetta and S. Conway Morris (eds.), The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Cambridge.

DZIK, J. Y., L. ZHAO AND M. Y. ZHU. 1997. Mode of life of the Middle Cambrian eldonioid lophophorate Rotadiscus. Palaeontology, 40(2):385-396.

MADSEN, F. J. 1956. Eldonia, a Cambrian siphonophore-formerly interpreted as a holoturian[sic]. Videnskabelige meddelelser fra Dansk naturhistorisk forening i Københaven, 118: 7-14.

MADSEN, F. J. 1957. On Walcott’s supposed Cambrian holothurians. Journal of Paleontology, 31(1): 281-282.

MADSEN, F. J. 1962. The systematic position of the Middle Cambrian fossil Eldonia. Meddelelser fra Dansk Geologisk Førening, 15: 87-89.

PAUL, C. R. C. AND A. B. SMITH. 1984. The early radiation and phylogeny of echinoderms. Biological Reviews, 59(4): 443-481.

WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian holothurians and medusae. Smithsonian Miscellaneous Collections, 57(3): 41-68.

ZHU, M. Y., Y. L. ZHAO AND J. Y. CHEN. 2002. Revision of the Cambrian discoidal animals Stellostomites eumorphus and Pararotadiscus guizhouensis from South China. Geobios, 35(2): 165-185.

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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:

Class: Trilobita (Order: Ptychopariida)
Remarks:

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

Species name: Ehmaniella burgessensis
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:

Period:
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:

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.

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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:

Class: Hexactinellida (Order: Reticulosa)
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.

Species name: Diagoniella hindei
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:

Period:
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:

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:

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Olenoides serratus

3D animation of Olenoides serratus.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Trilobita (Order: Corynexochida)
Remarks:

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

Species name: Olenoides serratus
Described by: Rominger
Description date: 1887
Etymology:

Olenoides – from Olenus, in Greek mythology a man who, along with his wife Lethaea, was turned to stone. Olenus was used for a trilobite genus name in 1827; the suffix –oides(“resembling”) was added later.

serratus – from the Latin serratus, “saw-shaped,” probably referring to the spinose margin of the pygidium.

Type Specimens: Type status under review – UMMP 4882 (11 specimens), University of Michigan Museum of Paleontology, Ann Arbor, Michigan, USA.
Other species:

Burgess Shale and vicinity: Kootenia dawsoni; Kootenia burgessensis. (Species of Kooteniaare no longer considered different enough from those in Olenoides to warrant placement in a separate genus, but Kootenia is retained here for ease of reference to historical literature).

Other deposits: species of Olenoides are widespread in the Cambrian of North America and Greenland, and have been recorded in Siberia, China, and elsewhere.

Age & Localities:

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

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

History of Research:

Brief history of research:

Olenoides serratus was among the first Burgess Shale animals to be named and described. The fossils used in Rominger’s original 1887 description were collected from the Mount Stephen Trilobite Beds in 1886. Rominger coined the name Ogygia serrata for this trilobite, illustrating one complete specimen in accompanying engravings. Following several intermediate changes, the name now in use was first published by Kobayashi in 1935. Spectacular appendage-bearing specimens discovered during Walcott’s Fossil Ridge excavations in 1910-1911 brought Olenoides serratus (then called Neolenus serratus) attention worldwide as one of the most anatomically complete trilobites known. This iconic Burgess Shale species has been thoroughly redescribed by Harry Whittington (1975, 1980), who also concluded that Nathorstia transitans (named by Walcott in 1912) was a “soft shell” moult stage of Olenoides serratus.

Description:

Morphology:

Hard parts: adult dorsal exoskeletons may reach 9 cm long and are broadly oval in outline, with a semi-circular cephalon, a thorax of seven segments ending in spines, and a semi-circular pygidium with marginal spines. The cephalon, thorax and pygidium are of approximately equal length. The parallel-sided glabella is rounded in front and reaches almost to the anterior border. Thin eye ridges swing back from the front of the glabella to the small, outwardly-bowed eyes. The free cheeks narrow back into straight, slender genal spines reaching to the third pleurae. Tips of the pleurae also extend into needle-like spines. The spiny pygidium has six axial rings decreasing in size backwards; five pairs of marginal spines point rearward. The whole exoskeleton has a variably granulate outer surface with fine ridges and cusps near the margins.

Unmineralized anatomy: Olenoides serratus had a pair of flexible, multi-jointed cephalic “antennae.” Behind these, three pairs of biramous limbs were attached beneath the cephalon on either side of the mid-line. Each inner branch had a large spiny blade-shaped coxa and six spinose cylindrical podomeres that tapered away from the body, the last carrying three short “claws” at the tip. The outer limb branch was composed of many flat, overlapping filaments sweeping back from a long lobe, with a small oval, hair-fringed lobe at the outer end. Pairs of similar biramous appendages were attached under each thoracic segments; four to six pairs were attached under the pygidium, becoming shorter and more slender to the rear. Unique among all trilobites preserving limbs, Olenoides serratus also had a pair of antenna-like appendages (cerci; singular = cercus) emerging from under the pygidium behind the last biramous limbs.

Abundance:

Olenoides serratus is moderately common, especially at the Mount Stephen Trilobite Beds, where thousands of pieces and hundreds of partial to complete exoskeletons have been observed or collected. Olenoides is the largest and most conspicuous trilobite in the Walcott Quarry section on Fossil Ridge, where specimens with preserved appendages have been found.

Maximum Size:
90 mm

Ecology:

Ecological Interpretations:

Adults of Olenoides serratus walked along the sea bed, possibly digging shallow furrows to locate small soft-bodied and weakly-shelled animals or carcasses. Prey items were shredded between the spiny limb bases and passed forward to the rear-facing mouth. Olenoides could probably swim just above sea bed for short distances. Some Olenoides fossils show unmistakable evidence of healed injuries, suggesting they may have been preyed upon, likely in their “soft-shell” growth phase, by larger arthropods such as Anomalocaris. Tiny larvae and early juveniles of Olenoides probably swam and drifted in the water column above the sea bed.

References:

KOBAYASHI, T. 1935. The Cambro-Ordovician formations and faunas of south Chosen. Paleontology, Part 3: Cambrian faunas of south Chosen with a special study on the Cambrian trilobite genera and families. Journal of the Faculty of Science, Imperial University of Tokyo, Section II. 4(2): 49-344.

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

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.

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. 1912. Cambrian Geology and Paleontology, II. No. 6. – Middle Cambrian Branchiopoda, Malacostraca, Trilobita, and Merostomata. Smithsonian Miscellaneous Collections, 57(6): 145-228.

WHITTINGTON, H. B. 1975. Trilobites with appendages from the Middle Cambrian, Burgess Shale, British Columbia. Fossils and Strata, No. 4: 97-136.

WHITTINGTON, H. B. 1980. Exoskeleton, moult stage, appendage morphology, and habits of the Middle Cambrian trilobite Olenoides serratus. Palaeontology, 23: 171-204.

Other Links:

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

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

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

http://pakozoic.deviantart.com/art/Olenoides-serratus-3D-77550691

Burgessochaeta setigera

Burgessochaeta setigera (ROM 61042) – Part and counterpart. Complete specimen showing gut contents and fecal material expelled from the anus (black strand visible on the counterpart, right images). Specimen length = 26 mm. Specimen wet – direct light (top row), wet – polarized light (bottom row). Walcott Quarry.

© Royal Ontario Museum. Photos: Jean-Bernard Caron

Taxonomy:

Class: Unranked clade (stem group polychaetes)
Remarks:

Burgessochaeta bears some resemblance to modern polychaetes but it cannot be placed in any extant group (Conway Morris, 1979; Eibye-Jacobsen, 2004) suggesting a position as a stem-group polychaete (Budd and Jensen, 2000).

Species name: Burgessochaeta setigera
Described by: Walcott
Description date: 1911
Etymology:

Burgessochaeta – from Mount Burgess (2,599 m), a mountain peak in Yoho National Park. Mount Burgess was named in 1886 by Otto Klotz, the Dominion topographical surveyor, after Alexander Burgess, a former Deputy Minister of the Department of the Interior. Also from the Latin chaeta, “bristle”, a common suffix for polychaete worms, reflecting spiny structures along their body.

setigera – from the Latin saetula, “small bristle.”

Type Specimens: Lectotype –USNM57650 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: none.

Age & Localities:

Period:
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:

First reported by Charles Walcott in 1911 and lumped into the genus Canadia (Walcott, 1911), Burgessochaeta was formally described as a separate genus by Simon Conway Morris in his 1979 treatise on the polychaetes of the Burgess Shale. Because it is rather common, Burgessochaeta has proven useful in calculating the extent of decay in fossil assemblages (Caron and Jackson, 2006).

Description:

Morphology:

This slender worm reached lengths of 1.8-4.9 cm (2.9 cm on average). Its width was constant (around 2 mm), except towards either end, where it tapered off. Its head bore a pair of long, smooth tentacles that reached 6 mm in length. The variation in shape seen among these tentacles suggests that the organism could contract and extend them. Its first segment also bears uniramous parapodia (paired single-branch appendages), while those of the other two dozen are biramous (divided into two). All of its body segments are similar to one another. Its parapodia bear in the range of 11-17 simple setae (usually 15), each about 2 mm in length, and which form a single plane that is inclined steeply with respect to the body. The tips of these setae form unequal forks, with one prong about half the length of the other. The animal had an unarmed eversible proboscis (prominent flexible apparatus capable of being turned inside-out like a tongue) that formed the front portion of its straight gut.

Abundance:

Burgessochaeta is relatively common in the Walcott Quarry representing 0.4% of the specimens counted in the community (Caron and Jackson, 2008).

Maximum Size:
49 mm

Ecology:

Ecological Interpretations:

Burgessochaeta probably burrowed or moved along the surface of the mud, using its short parapodia. Its tentacles are thought to have been used to collect food; the presence of sediment in its gut suggests that it might have been a deposit feeder.

References:

BUDD, G. E. AND S. JENSEN. 2000. A critical reappraisal of the fossil record of the bilaterian phyla. Biological Reviews, 75: 253-295.

CARON, J.-B. AND D. A. JACKSON. 2006. Taphonomy of the Greater Phyllopod Bed Community, Burgess Shale. PALAIOS, 21: 451-465.

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: 317-335.

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

Other Links:

None

Nisusia burgessensis

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

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Kutorginata (Order: Kutorginida)
Remarks:

Nisusia belongs within the Family Nisusiidae.

Species name: Nisusia burgessensis
Described by: Walcott
Description date: 1889
Etymology:

Nisusia – from the Latin, nisus, meaning “labored, or striven.”

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

Type Specimens: Syntypes –USNM69690-69697 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: Nisusia alberta from the Trilobite Beds on Mount Stephen (Walcott, 1905, 1908). 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-Middle Cambrian of North America, Greenland, Russia, China and Australia.

Age & Localities:

Period:
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:

Nisusia burgessensis was originally described as Orthisina alberta (Walcott, 1889) before being renamed Nisusia alberta (Walcott, 1905). Specimens of this species identified from the Walcott Quarry (Walcott, 1912) were re-described by Walcott as Nisusia burgessensis(Walcott, 1924), a combination still in use today. This species has not been studied since and is in need of revision.

Description:

Morphology:

This species has fine radiating ornamental lines (costae) and concentric lines of growth. The shell was originally mineralized. It is roughly 1.5 wider than its length. Both valves are convex, but the convexity of the ventral shell is more pronounced. The shells would have been articulated with short and small teeth, like in Diraphora, a comparable form from the Burgess Shale. Very thin bristles (setae) are present in a single specimen at the front of the shell margin. These would have been attached to the edge of the mantle along both the dorsal and ventral valves in the same way as in Micromitra.

Abundance:

Nisusia burgessensis is relatively common in the Walcott Quarry but overall represents a small fraction of the fauna (<0.3%) (Caron and Jackson, 2008).

Maximum Size:
23 mm

Ecology:

Ecological Interpretations:

Nisusia probably had a relatively short, stout pedicle attached either to the substrate or to other organisms like the sponge Pirania, to raise it above the sediment-water interface. In this way the brachiopod would have been relatively protected from flocculent mud travelling along the sediment-water interface, which could have been detrimental to its filter-feeding apparatus (located between the shells) called a lophophore. The bristles (setae) might have also helped reduce the intake of mud particles into the filter-feeding apparatus.

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. 1889. Description of new genera and species of fossils from the Middle Cambrian. United States National Museum, Proceedings for 1888: 441-446.

WALCOTT, C. 1905. Cambrian brachiopods with descriptions of new genera and species. United States National Museum, Proceedings for 1905: 227-337.

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

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

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

Other Links:

None

Naraoia compacta

Reconstruction of Naraoia compacta.

© MARIANNE COLLINS

Taxonomy:

Class: Unranked clade (stem group arthropods)
Remarks:

Naraoia is usually compared to the trilobites, but its exact relationships are uncertain (Whittington, 1977). The naraoiids and other trilobite-like arthropods, sometimes referred to as Trilobitoidea, can be grouped together with the trilobites to 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).

Species name: Naraoia compacta
Described by: Walcott
Description date: 1912
Etymology:

Naraoia – from Narao Lakes, near Kicking Horse Pass in Yoho Park, British Columbia. From the Stoney First Nation Nakoda word Narao, meaning “hit in the stomach,” which likely refers to James Hector, who was kicked by a horse while travelling up the Kicking Horse River in 1858.

compacta – from the Latin compactus, “joined together.”

Type Specimens: Lectotype –USNM57687 (N. compacta) and holotypesUSNM83946 (N. spinifer) andUSNM189210 (N. halia) in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: N. spinifer (Walcott, 1931); N. halia (Simonetta and Delle Cave, 1975) from the Walcott Quarry, Burgess Shale.

Other deposits: N. longicaudata and spinosa (Zhang and Hou, 1985) from the Early Cambrian Chengjiang biota of South China, of which N. longicaudata was later placed in its own genus, Misszhouia (Chen et al., 1997); Possible specimens of Naraoia have been found at the Lower Cambrian Emu Bay Shale in Australia (Nedin, 1999). Unlike most Burgess Shale arthropods, Naraoia has also been found in rocks younger than the Cambrian, in the Late Silurian Bertie Formation of Southern Ontario (Caron et al., 2004).

Age & Localities:

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

The Walcott and Raymond Quarries on Fossil Ridge. The Trilobite Beds on Mt. Stephen, Tulip Beds (S7) and Collins Quarry as well as other smaller localities on Mount Stephen.

History of Research:

Brief history of research:

The first description of Naraoia was N. compacta by Walcott (1912), who later described a second specimen, N. spinifer (1931). Simonetta and Delle Cave (1975) re-examined the specimens and designated the new species N. halia and N. pammon. A major redescription of all Burgess Shale material was undertaken by Whittington (1977), and N. compactaspecimens from the Marjum Formation in Utah and the Gibson Formation in Idaho were described by Robison (1984), both of whom synonymized N. halia and N. pammon with N. compacta. However, a major restudy of the naraoiids by Zhang et al. (2007) concluded that N. halia is actually a valid species.

Description:

Morphology:

Naraoia consists of two dorsal shields with a convex axial region, including a roughly square head shield and an elongated body shield. A pair of long, multi-jointed antennae emerges from beneath the head shield. Behind the antennae are four pairs of cephalic appendages and 14 pairs of trunk appendages. All these appendages are segmented and branch into two (biramous), with a spiny walking limb made up of seven segments, and a filamentous branch consisting of a thin shaft bearing many lamellae (flexible and elongated plate-like elements). The basal segment of the biramous appendage is composed of a large, spiny plate.

Internal structures of Naraoia are well preserved, with the most conspicuous feature being the complexly branched gut glands visible on the cephalic shield. The gut passes along the whole length of the body, with paired gut glands visible in the anterior half.

Abundance:

Hundreds of specimens of Naraoia are known from the Walcott Quarry, where they make up about 0.74% of the community (Caron and Jackson, 2008). Naraoia is rare in all the other known localities.

Maximum Size:
40 mm

Ecology:

Ecological Interpretations:

Naraoia likely spent much of its time walking on the sea floor, since the rigidity of its appendages would only allow for limited periods of swimming. It would have sensed its environment, including food items, using its antennae. Naraoia used the segmented walking limbs of its biramous appendages for walking and for manipulating food items, which were crushed and moved towards the mouth using the spiny basal plate. The filamentous branches of the biramous limb were used for gas exchange and to propel the animal through the water during short burst of swimming. The large gut glands and spiny appendages suggest that Naraoia was a predator or scavenger. Specimens with healed injuries suggest that Naraoia was also a prey item for other larger predators.

References:

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

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., D. M. RUDKIN AND S. MILLIKEN. 2004. A new Late Silurian (Pridolian) naraoiid (Euarthropoda: Nektaspida) from the Bertie Formation of southern Ontario, Canada – delayed fallout from the Cambrian explosion. Journal of Paleontology, 78: 1138-1145.

CHEN, J. G. D. EDGECOMBE AND L. RAMSKöLD. 1997. Morphological and ecological disparity in naraoiids (Arthropoda) from the Early Cambrian Chengjiang fauna, China. Records of the Australian Museum, 49: 1-24.

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.

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

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

NEDIN, C. 1999. Anomalocaris predation on nonmineralized and mineralized trilobites. Geology, 27: 987-990.

ROBISON, R. B. 1984. New occurrence of the unusual trilobite Naraoia from the Cambrian of Idaho and Utah. University of Kansa Paleontological Contribution, 112: 1-8.

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

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

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.

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.

ZHANG, W. AND X. HOU. 1985. Preliminary notes on the occurrence of the unusual trilobite Naraoia in Asia. Acta Palaeontologica Sinica, 24: 591-595.

ZHANG, X., D. SHU AND D. H. ERWIN. 2007. Cambrian naraoiids (Arthropoda): Morphology, ontogeny, systematics and evolutionary relationships. Journal of Paleontology, 81:1-52.

Other Links:

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

Morania confluens

3D animation of Morania confluens (being grazed by Wiwaxia corrugata).

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Cyanophyceae (Order: Nostocales?)
Remarks:

Walcott (1919) considered Morania to be related to the modern cyanobacteria Nostoc. No revisions to the affinities of this cyanobacterium have been published since.

Species name: Morania confluens
Described by: Walcott
Description date: 1919
Etymology:

Morania – from Moraine Lake (1,885 m), in Banff National Park.

confluens – from the Latin fluere, “flow or stream,” and the prefix con, “together.” The name refers to the abundance of this species.

Type Specimens: Syntypes–USNM35378-35390, 35398 (M. confluens); USMN 35391, 35392 (M. costellifera);USNM35393 (M. elongata);USNM35394 (M. fragmenta);USNM35395 – 35397, 35401 (M.? globosa);USNM57718 (M. parasitica);USNM35402 (M.? reticulata) in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: M. costellifera Walcott, 1919; M. elongata Walcott, 1919; M. fragmenta Walcott, 1919; M.? globosa Walcott, 1919; M. parasitica Walcott, 1919; M.? reticulata Walcott, 1919, all from the Walcott Quarry.

Other deposits: M.? antiqua Fenton and Fenton, 1937 from the middle Proterozoic Altyn Limestone of Montana and the Little Dal Group, Mackenzie Mountains (see Hofmann and Aitken, 1979).

Age & Localities:

Period:
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 described Morania, erecting eight species, in a 1919 paper along with Burgess Shale algae, comparing the genus to the extant cyanobacteria Nostoc. Walcott included thin sections and details of the microstructures of M. confluens showing that it was formed of tangled strings of pyrite. Satterthwait (1976) studied specimens of M. confluens from the Geological Survey of Canada collections as part of her PhD thesis and broadly agreed with Walcott’s original interpretations, in particular regarding a position within the Nostocaceae. Sattertwhait’s work has not been published but she suggested that many species erected by Walcott might not be valid and could represent parts of more complex algae. Mankiewicz (1992) re-observed Walcott’s thin sections and confirmed the presence of Morania in several samples. Rigby (1986) identified M.? frondosa Walcott 1919, as a sponge and reassigned it to a new genus (see Crumillospongia frondosa).

Description:

Morphology:

Morania ranges in shape from spherical to sheet-like. The sheet-like form M. confluens is by far the most common species. Specimens typically range in length between 1 to more than 13 centimeters. The sheets are characteristically perforated, with holes up to 3 centimeters in diameter. The shape, size, number and distribution of holes are highly variable. Thin sections show that the microstructure of M. confluens is represented by a tangle mass of filaments called trichomes. These filaments have a beadlike structure with little spheroids of pyrite ranging 3 to 7 micrometers in diameter, and originally interpreted by Walcott as defining cellular structures.

Abundance:

Estimating the abundance of Morania is difficult since some bedding planes have large tangled masses of this cyanobacterium, and many could represent fragments of the same colony. Morania is very common in the Walcott Quarry and represents 4.9% of the community (Caron and Jackson, 2008).

Maximum Size:
130 mm

Ecology:

Ecological Interpretations:

Caron and Jackson (2006) suggested that Morania covered large areas of the benthos and might have provided a stable substrate and food source for benthic animals, in particular for a number of grazers, like Odontogriphus and Wiwaxia.

References:

CARON, J.-B. AND D. A. JACKSON. 2006. Taphonomy of the Greater Phyllopod Bed Community, Burgess Shale. Palaios, 21: 451-465.

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

HOFMANN, H. J. AND J. D. AITKEN. 1979. Precambrian biota from the Little Dal Group, Mackenzie Mountains, northwestern Canada. Canadian Journal of Earth Sciences, 16: 150-166.

MANKIEWICZ, C. 1992. Obruchevella and other microfossils in the Burgess Shale: preservation and affinity. Journal of Paleontology, 66(5): 717-729.

SATTERTHWAIT, D. F. 1976. Paleobiology and Paleoecology of Middle Cambrian Algae from Western North America. Unpublished PhD thesis, California, Los Angeles, 120 p.

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

Other Links:

None