The Burgess Shale

Selkirkia columbia

3D animation of Selkirkia columbia.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Unranked clade (stem group priapulids)
Remarks:

Selkirkia has been compared to the nemathelminth worms (Maas et al., 2007), but most analyses support a relationship with the priapulids at a stem-group level (Harvey et al., 2010; Wills, 1998).

Species name: Selkirkia columbia
Described by: Walcott
Description date: 1911
Etymology:

Selkirkia – from the Selkirk Mountains, a mountain range in southeastern British Columbia.

columbia – from British Columbia, where the Burgess Shale is located.

Type Specimens: Holotype –USNM57624 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: The genus Selkirkia ranges from the Lower to the Middle Cambrian and is represented by several species, including S. sinica from the Lower Cambrian Chengjiang Biota (Luo et al., 1999; Maas et al., 2007), S. pennsylvanica from the Lower Cambrian Kinzers Formation (Resser and Howell, 1938), Selkirkia sp. cf. and S. spencei from the Middle Cambrian Spence Shale of Utah (Resser, 1939; Conway Morris and Robison, 1986, 1988), and S. willoughbyi from the Middle Cambrian Marjum Formation of Utah (Conway Morris and Robison, 1986).

Age & Localities:

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

Burgess Shale and vicinity: The Walcott, Raymond and Collins Quarries on Fossil Ridge, and smaller localities on Mount Field and Mount Odaray. The Trilobite Beds, the Collins Quarry, the Tulip Beds (S7) and smaller localities on Mount Stephen.

Other deposits: The Middle Cambrian Spence Shale of Utah (Resser, 1939; Conway Morris and Robison, 1986, 1988).

History of Research:

Brief history of research:

Charles Walcott (1908) illustrated a single specimen of a simple tube that he named “Orthotheca major.” He interpreted the fossil as the tube of a polychaete worm, along with another famous species, “O. corrugata,” described by Matthew a decade earlier. O. corrugata is now referred to as Wiwaxia corrugata, which is not the tube of a worm but the scale of an armoured mollusc! The original specimen of “O. major” came from the Trilobite Beds on Mount Stephen, but it was not until the discovery of complete specimens from Fossil Ridge showing soft-bodied worms within the tubes that more details about this animal became available. Walcott (1911) created a new genus name Selkirkia to accommodate the new fossil material. In addition to the type species, S. major, he named two new species, S. gracilis and S. fragilis. In a revision of Walcott’s collections and other fossils discovered by the Geological Survey of Canada, Conway Morris (1977) synonymised Walcott’s three species into one that he called S. columbia, which is still in use today. S. columbia was described as a primitive priapulid worm (Conway Morris, 1977); later studies showed that it belongs to the priapulid stem group (Wills, 1998; Harvey et al., 2010).

Description:

Morphology:

Selkirkia lived in a tube and could reach up to 6 centimetres in length. The body of the worm itself is similar to most priapulids in having a trunk (which remained in the tube) and an anterior mouthpart that could be inverted into the trunk, called a proboscis. The proboscis has different series of spines along its length and is radially symmetrical. Small body extensions called papillae are present along the anterior part of the trunk and probably helped in anchoring the trunk in the tube. The gut is straight and the anus is terminal. The unmineralized tube is slightly tapered, open at both ends, and bears fine transverse lineations.

Abundance:

Selkirkia is the most abundant priapulid in the Walcott Quarry community, representing 2.7% of the entire community (Caron and Jackson, 2008); thousands of specimens are known, mostly isolated tubes.

Maximum Size:
60 mm

Ecology:

Ecological Interpretations:

The well developed proboscis and strong spines suggest a carnivorous feeding habit. Comparisons with modern tube-building priapulids suggest Selkirkia was capable of only limited movement, and spend most of the time buried vertically or at an angle to the sediment-water interface, where they might have “trap fed” on live prey. Empty tubes were often used as a substrate for other organisms to colonize, for example, brachiopods, sponges and primitive echinoderms (see Echmatocrinus).

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

CONWAY MORRIS, S. AND R. A. ROBISON. 1986. Middle Cambrian priapulids and other soft-bodied fossils from Utah and Spain. The University of Kansas paleontological contributions, 117: 1-22.

CONWAY MORRIS, S. AND R. A. ROBISON. 1988. More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia. University of Kansas Paleontological Contributions, Paper, 122: 23-48.

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

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.

MAAS, A., D. HUANG, J. CHEN, D. WALOSZEK AND A. BRAUN. 2007. Maotianshan-Shale nemathelminths – Morphology, biology, and the phylogeny of Nemathelminthes. Palaeogeography, Palaeoclimatology, Palaeoecology, 254(1-2): 288-306.

RESSER, C. E. AND B. F. HOWELL. 1938. Lower Cambrian Olenellus Zone of the Appalachians. Geological Society of America, Bulletin, 49: 195-248.

RESSER, C. E. 1939. The Spence Shale and its fauna. Smithsonian Miscellaneous Collections, 97(12):1-29.

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

WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-145.

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

Other Links:

None

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:

Class: Unranked clade (stem group priapulids)
Remarks:

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

Species name: Scolecofurca rara
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:

Period:
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:

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

Fieldia lanceolata

Fieldia lanceolata (ROM 32572) – Part (left) and counterpart (right). Complete specimen with anterior section burried vertically, the posterior is to the left on the part. Specimen length (preserved) = 38 mm. Specimen wet – direct light (top row), wet – polarized light (bottom row). Walcott Quarry talus.

© Royal Ontario Museum. Photos: Jean-Bernard Caron

 

Taxonomy:

Class: Unranked clade (stem group priapulids)
Remarks:

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

Species name: Fieldia lanceolata
Described by: Walcott
Description date: 1912
Etymology:

Fieldia – from Field, the mountain peak (2,643 m) and small town near Fossil Ridge, British Columbia, Canada. The name was given by William Cornelius Van Horne (General Manager of the Canadian Pacific Railway), to honour Cyrus West Field, a promoter of the first telegraph cable across the Atlantic Ocean.

lanceolata – from the Latin lanceolatus, “lance-shaped,” in reference to the shape of the worm.

Type Specimens: Holotype –USNM57717 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:

Walcott (1912) was the first to describe Fieldia, which he mistook for the carapace of a crustacean. He later classified a different specimen with the priapulid Ancalagon (known then as “Ottoia minor” Walcott, 1931). Conway Morris (1977) re-described the genus as a primitive priapulid worm based on new material he had found in the Smithsonian’s collections; later studies showed that it belonged to the priapulid stem group (Harvey et al., 2010; Wills, 1998).

Description:

Morphology:

Fieldia is a cylindrical worm about five centimeters in length, with a spine-covered body (trunk) and a rather small, eversible mouthpart, called a proboscis. The proboscis is lined with small spines at the front and several rows of hooks posteriorly. It is not known if the proboscis could be fully retracted or inverted as in other fossil and Recent priapulid worms. The gut is often preserved with a mud infill, and runs along the centre of the body. The trunk does not have annulations and is divided into an anterior, middle and a posterior part. The mud infill is most conspicuous in the middle part of the trunk.

Abundance:

This species is very rare. Only a single specimen was originally described by Walcott (1912) and about a dozen specimens were studied by Conway Morris (1977).

Maximum Size:
53 mm

Ecology:

Ecological Interpretations:

Fieldia is commonly preserved with mud inside its gut, suggesting that it fed directly on the sea-floor sediments. Its tubular body-shape is well adapted for burrowing; it probably used its spines to pull itself through the mud.

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.

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

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

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

Other Links:

None

Ottoia prolifica

3D animation of Ottoia prolifica.

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Unranked clade (stem group priapulids)
Remarks:

Ottoia has been compared to the nemathelminth worms (Maas et al., 2007), but most analyses support a relationship with the priapulids at a stem-group level (Harvey et al., 2010; Wills, 1998).

Species name: Ottoia prolifica
Described by: Walcott
Description date: 1911
Etymology:

Ottoia – from Otto Pass (2,106 m), a few kilometres north-west of the Burgess Shale. The pass was named after Otto Klotz, an astronomer working for the Department of the Interior along the Canadian Pacific Railroad (read about Otto Klotz in the section “First Discoveries”)

prolifica – from the Latin proles, “offspring,” and ferax, “rich, fruitful,” in reference to the great number of specimens discovered.

Type Specimens: Lectotype –USNM57619 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none

Other deposits: Ottoia sp. from the Lower Cambrian Pioche Shale, Nevada (Lieberman, 2003).

Age & Localities:

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

Burgess Shale and vicinity: The Walcott and Raymond Quarries on Fossil Ridge, the Collins Quarry, the Tulip Beds (S7) and smaller localities on Mount Stephen. Smaller localities on Mount Field, Mount Odaray and Monarch Cirque.

Other deposits: The same species also occurs in the Middle Cambrian Spence Shale and Marjum Formations, Utah (Conway Morris and Robison, 1986).

History of Research:

Brief history of research:

Charles Walcott (1911) first described Ottoia as a tentative member of the now-dismantled grouping of worms called the Gephyrea, which included the priapulids as well as the sipunculans and echiurans. He emphasized a comparison with the sipunculans, leading some subsequent authors to consider it as a member of this phylum; others, however, suggested affinities with the parasitic acanthocephalans, or the priapulids (Banta and Rice, 1970). A re-analysis of the fossil material itself was not conducted until the 1970s, with work by Banta and Rice (1970) and Conway Morris (1977) supporting a relationship with the priapulids, which was later demonstrated to be at a stem-group level (Wills, 1998). Other work has focussed on the ecology of the Burgess Shale representatives (Bruton, 2001; Vannier, 2009; Vannier et al., 2010).

Description:

Morphology:

Ottoia is a priapulid worm with a tooth-lined mouthpart (proboscis) that could be inverted into the trunk; a short posterior tail extension could also be inverted. Ottoia reached 15 cm in length; the smallest specimens – presumably juveniles, but identical to adults – were just 1 cm long. The proboscis was adorned with 28 rows of hooks interspersed with a variety of spines. The worms are usually found curved into a U-shape, with their sediment-filled guts often visible running down the centre of the organism. The trunk was annulated, and bore two sets of four hooks arranged in a ring towards the rear end; these are the only traces of bilateral symmetry, with a radial symmetry superimposed on the organism. Ottoiaperiodically shed its cuticle to allow growth.

Abundance:

Ottoia is one of the more abundant Burgess Shale organisms, accounting for over 80% of the Walcott Quarry priapulids (Conway Morris, 1977) and over 1.3% of the entire Walcott Quarry community (Caron and Jackson, 2008); thousands of specimens are known.

Maximum Size:
150 mm

Ecology:

Ecological Interpretations:

Specimens of Haplophrentis carinatus preserved in the gut indicate that this hyolith was a staple of the Ottoia diet (Conway Morris, 1977). One fossil slab also shows nine specimens feeding on a recently-dead Sidneyia carcass (Bruton, 2001).

References:

BANTA, W. C. AND M. E. RICE. 1970. A restudy of the Middle Cambrian Burgess Shale fossil worm, Ottoia prolifica. International Symposium on the Biology of the Sipuncula and Echiura 2, Kotor: 79-90.

BRUTON, D. L. 2001. A death assemblage of priapulid worms from the Middle Cambrian Burgess Shale. Lethaia, 34(2):163-167.

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

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

CONWAY MORRIS, S. AND J. S. PEEL. 2009. New Palaeoscolecidan Worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale. Acta Palaeontologica Polonica, 55(1): 141-156.

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

MAAS, A., D. HUANG, J. CHEN, D. WALOSZEK AND A. BRAUN. 2007. Maotianshan-Shale nemathelminths – Morphology, biology, and the phylogeny of Nemathelminthes. Palaeogeography, Palaeoclimatology, Palaeoecology, 254(1-2): 288-306.

WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-145.

Other Links:

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

Ancalagon minor

Ancalagon minor (USNM 57646) – Holotype (part and counterpart). Left, plate 22 of Walcott (1911), showing a retouched image of the original specimen (upside down) (figure 5). Right, images of the same specimen showing a dark stain, probably representing decay fluids at the posterior end of the body. Specimen length = 70 mm. Specimen dry – direct light (top), dry – polarized light (middle, bottom). Walcott Quarry.

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

Taxonomy:

Class: Unranked clade (stem group priapulids)
Remarks:

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

Species name: Ancalagon minor
Described by: Walcott
Description date: 1911
Etymology:

Ancalagon – from Ancalagon the Black, a dragon in Tolkien’s fantasy writings (The Fellowship of the Ring, 1954; The Silmarillion, 1977), in reference to the worm’s strong rows of hooks.

minor – from the Latin minor, “inferior,” in reference to the small size of the worm.

Type Specimens: Holotype –USNM57646 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:

Walcott (1911, 1931) described and illustrated several specimens of this species as “Ottoia minor.” However, this species was pulled from the genus Ottoia to Ancalagon by Conway Morris (1977) and re-described as a primitive priapulid worm; later studies showed that it belongs to the priapulid stem group (Harvey et al., 2010; Wills, 1998).

Description:

Morphology:

The tubular body of this worm can reach up to 11 centimeters and is divided into a finely annulated trunk and an anterior eversible mouthpart, called a proboscis. The proboscis bears strong hooks at the front, and smaller hooks pointing backwards posteriorly. Fine hair-like setae are present on the trunk. The gut is straight and the anus is terminal.

Abundance:

This species is rare – less than 20 specimens are known.

Maximum Size:
110 mm

Ecology:

Ecological Interpretations:

The tubular body-shape is well adapted for burrowing; Ancalagon probably used its spines to pull itself through the mud. The strong hooks at the front of the proboscis suggest a carnivorous feeding habit.

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.

WALCOTT, C. 1911. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-145.

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

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

Other Links:

None

Louisella pedunculata

Reconstruction of Louisella pedunculata.

© MARIANNE COLLINS

Taxonomy:

Class: Unranked clade (stem group priapulids)
Remarks:

Louisella has been compared to the nemathelminth worms (Maas et al., 2007), but most analyses support a relationship with the priapulids at a stem-group level (Harvey et al., 2010; Wills, 1998).

Species name: Louisella pedunculata
Described by: Walcott
Description date: 1911
Etymology:

Louisella – from Lake Louise, a lake near the Burgess Shale that was named after Princess Louise Caroline Alberta (1848-1939), the wife of the Governor General of Canada Marquis of Lorne and Queen Victoria’s fourth daughter.

pedunculata – from the Latin diminutive pedunculus, “foot,” in reference to small foot-like structures (papillae) along the body.

Type Specimens: Holotype –USNM57558 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:

When he first described it in 1911,Walcott originally considered his single specimen of Louisella to be a sea-cucumber, recognizing a flattened “sole” and tentacles at either end (Walcott, 1911a); unusual folding of the Louisella holotype had given its rows of papillae (“pimples”) the appearance of tentacles at the front and back. He subsequently described additional material as a new annelid worm, Miskoia preciosa (Walcott, 1911b), but this was eventually synonymised with Louisella by Conway Morris (1977) who recognized it as a primitive priapulid worm.

Description:

Morphology:

Louisella is the largest priapulid in the Burgess Shale, reaching 30 cm in length. Like all priapulids, the organism is an annulated worm with an invertable, tooth-lined feeding structure (proboscis) at the front end of the body; it had a straight gut leading directly from the mouth at the front to the anus at the rear. The trunk of the worm displayed four discrete sections, distinguished by their surface texture. Rings of short spines encircled the body of the worm, and two rows of pimples (papillae – possibly used as gills) extended along one surface of the worm. The rear-most portion of the organism did not possess spines, and could be inverted into the tail end of the animal. The proboscis itself was covered with an array of spines, with a ring of twenty-five longer spikes near its midlength. It could be turned inside-out (everted) and extruded from the organism.

Abundance:

This species is only known in the Walcott Quarry where it is relatively rare, representing 0.09% of the specimens counted in the community (Caron and Jackson, 2008).

Maximum Size:
300 mm

Ecology:

Ecological Interpretations:

Louisella was a burrowing worm, possibly spending some time on the surface. It was carnivorous, and its proboscis seems to be suited to grinding food, suggesting that it fed on larger prey items. However, it is not clear whether Louisella was an active hunter, or scavenged on dead carcasses. Possible sediment in the gut suggests that it may have fed on organisms within the sediment, or ingested mud as it fed – although the mud may have entered after death.

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

CONWAY MORRIS, S. AND J. S. PEEL. 2009. New Palaeoscolecidan Worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale. Acta Palaeontologica Polonica, 55(1): 141-156.

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

MAAS, A., D. HUANG, J. CHEN, D. WALOSZEK AND A. BRAUN. 2007. Maotianshan-Shale nemathelminths – Morphology, biology, and the phylogeny of Nemathelminthes. Palaeogeography, Palaeoclimatology, Palaeoecology, 254(1-2): 288-306.

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

WALCOTT, C. 1911b. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-145.

Other Links:

None

Louisella pedunculata

Template is not defined.

Taxonomy:

Class: Unranked clade (stem group priapulids)
Affinity:

Louisella has been compared to the nemathelminth worms (Maas et al., 2007), but most analyses support a relationship with the priapulids at a stem-group level (Harvey et al., 2010; Wills, 1998).

Species name: Louisella pedunculata
Described by: Walcott
Description date: 1911
Etymology:

Louisella – from Lake Louise, a lake near the Burgess Shale that was named after Princess Louise Caroline Alberta (1848-1939), the wife of the Governor General of Canada Marquis of Lorne and Queen Victoria’s fourth daughter.

pedunculata – from the Latin diminutive pedunculus, “foot,” in reference to small foot-like structures (papillae) along the body.

Type Specimens: Holotype –USNM57558 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:

When he first described it in 1911,Walcott originally considered his single specimen of Louisella to be a sea-cucumber, recognizing a flattened “sole” and tentacles at either end (Walcott, 1911a); unusual folding of the Louisella holotype had given its rows of papillae (“pimples”) the appearance of tentacles at the front and back. He subsequently described additional material as a new annelid worm, Miskoia preciosa (Walcott, 1911b), but this was eventually synonymised with Louisella by Conway Morris (1977) who recognized it as a primitive priapulid worm.

Description:

Morphology:

Louisella is the largest priapulid in the Burgess Shale, reaching 30 cm in length. Like all priapulids, the organism is an annulated worm with an invertable, tooth-lined feeding structure (proboscis) at the front end of the body; it had a straight gut leading directly from the mouth at the front to the anus at the rear. The trunk of the worm displayed four discrete sections, distinguished by their surface texture. Rings of short spines encircled the body of the worm, and two rows of pimples (papillae – possibly used as gills) extended along one surface of the worm. The rear-most portion of the organism did not possess spines, and could be inverted into the tail end of the animal. The proboscis itself was covered with an array of spines, with a ring of twenty-five longer spikes near its midlength. It could be turned inside-out (everted) and extruded from the organism.

Abundance:

This species is only known in the Walcott Quarry where it is relatively rare, representing 0.09% of the specimens counted in the community (Caron and Jackson, 2008).

Maximum Size:
300 mm

Ecology:

Ecological Interpretations:

Louisella was a burrowing worm, possibly spending some time on the surface. It was carnivorous, and its proboscis seems to be suited to grinding food, suggesting that it fed on larger prey items. However, it is not clear whether Louisella was an active hunter, or scavenged on dead carcasses. Possible sediment in the gut suggests that it may have fed on organisms within the sediment, or ingested mud as it fed – although the mud may have entered after death.

References:

Bibliography:

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

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

CONWAY MORRIS, S. AND J. S. PEEL. 2009. New Palaeoscolecidan Worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale. Acta Palaeontologica Polonica, 55(1): 141-156.

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

MAAS, A., D. HUANG, J. CHEN, D. WALOSZEK AND A. BRAUN. 2007. Maotianshan-Shale nemathelminths – Morphology, biology, and the phylogeny of Nemathelminthes. Palaeogeography, Palaeoclimatology, Palaeoecology, 254(1-2): 288-306.

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

WALCOTT, C. 1911b. Cambrian Geology and Paleontology II. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-145.

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