The Burgess Shale

Acanthotretella spinosa

Reconstruction of Acanthotretella spinosa.

© MARIANNE COLLINS

Taxonomy:

Class: Lingulata (Order: Siphonotretida, stem group brachiopods)
Remarks:

Acanthotretella spinosa is probably related to a primitive group of brachiopods of the Order Siphonotretida (Holmer and Caron, 2006).

Described by: Holmer and Caron
Description date: 2006
Etymology:

Acanthotretella – from the Greek akantha, “thorn,” and tretos, “perforated,” and the Latin diminutive ella, describing the small, perforated, spiny shell.

spinosa – from the Latin spinosus, referring to the exterior spines.

Type Specimens: Holotype –ROM57749 in the Royal Ontario Museum, Toronto, Canada.
Other species:

Burgess Shale and vicinity: none.

Other deposits: Acanthotretella decaius from the early Cambrian Guanshan fauna, China.

Age & Localities:

Species name: Acanthotretella spinosa
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:

Specimens were first illustrated as Lingulella sp. by Jin, et al. (1993), and formally described as Acanthotretella spinosa by Holmer and Caron (2006). New characters preserved in a related species from China (Acanthotretella decaius, Zhifei et al., 2010) reinforce the probable position of this genus within the Order Siphonotretida.

Description:

Morphology:

The shell of Acanthotretella is mainly organic in composition with probably only minor organo-phosphatic mineralization, and is ventri-biconvex. Both valves are covered in long, slender spines that penetrate the shell and are posteriorly inclined, angled obliquely away from the anterior margin. A long, flexible pedicle emerges from an external tube that extends from the pedicle foramen along the ventral valve. The pedicle is at least three to four times the length of the valves. The visceral area of both valves is short and triangular, and does not extend to mid-valve. Other interior features are poorly known.

Abundance:

Most specimens come from the Walcott Quarry and represent one of the rarest brachiopods with less than 0.05% of the entire fauna (Caron and Jackson, 2008).

Maximum Size:
8 mm

Ecology:

Ecological Interpretations:

The long, thin pedicle and overall shell shape probably preclude an infaunal habit. Pedicles of several specimens were found attached at the terminal bulb to organic structures, suggesting that Acanthotretella spinosa was epibenthic. The pedicle was likely able to maintain the shell in an upright position well above the sediment-water interface. Extraction of food particles from the water would have been possible thanks to a filter-feeding apparatus (located between the shells) called a lophophore.

References:

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

HU, S. X., Z. F. ZHANG, L. E. HOLMER AND C. B. SKOVSTED. 2010. Soft-part preservation in a linguliform brachiopod from the lower Cambrian Wulongqing Formation (Guanshan Fauna) of Yunnan, South China. Acta Palaeontologica Polonica, 55: 495-505.

HOLMER, L. E. AND J.-B. CARON. 2006. A spinose stem-group brachiopod with pedicle from the Middle Cambrian Burgess Shale. Acta Zoologica (Stockholm), 87: 273-290.

JIN, Y. G, X. G. HOU. AND H. Y. WANG. 1993. Lower Cambrian pediculate lingulids from Yunnan, China. Journal of Paleontology, 67: 788-798.

Other Links:

http://onlinelibrary.wiley.com/doi/10.1111/j.1463-6395.2006.00241.x/abstract

Paterina zenobia

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

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Paterinata (Order: Paterinida)
Remarks:

A brachiopod within the family Paterinidae.

Species name: Paterina zenobia
Described by: Walcott
Description date: 1912
Etymology:

Paterina – from the Latin word pater, “father,” because the species was considered the ancestor of modern brachiopods, and the diminutive suffix, – ina, “derived from.”

zenobia – possibly from the Greek, Zeon, a form of Zeus.

Type Specimens: Syntype–USNM58311; plesiotypesUSNM56907, 51483, 69631- 69637 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: None to date. The Burgess Shale brachiopods, in particular from the Trilobite Beds on Mount Stephen, need to be re-examined (see also Brief history of research).

Other deposits: Several species are known in the Lower to the Middle Cambrian worldwide.

Age & Localities:

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

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

History of Research:

Brief history of research:

Walcott originally assigned specimens collected from the Burgess Shale and Mount Stephen to Micromitra zenobia Walcott (1912) and a subspecies of Paterina stissingensis, called Paterina stissingensis ora Walcott (1912). Both taxa were redescribed as Paterina zenobia by Resser (1938), a combination still in use today. However, close similarities between species of the two genera have created difficulties in defining their specific characteristics, which have resulted in many incorrectly identified specimens.

Description:

Morphology:

Paterina is the type genus of one of the earliest and most primitive brachiopod groups, the Paterinata. Unlike many modern brachiopods, its hinge line is straight and crosses almost the full width of the shell. The moderately biconvex shell grows consistently, rather than showing separate stages of development. Its exterior growth lines are coarse and regular. Faint radial ridges are present at the apex of some adult specimens. No preserved soft parts are known and the shell was originally mineralized.

Abundance:

This species is rare in the Walcott Quarry and represents a very small fraction of the entire fauna (<0.05%) (Caron and Jackson, 2008).

Maximum Size:
11 mm

Ecology:

Ecological Interpretations:

Paterina probably attached to the substrate by a very short stalk. Paterina extracted food particles from the water with its filter-feeding apparatus (located between the shells) called a lophophore.

References:

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

RESSER, C. E. 1938. Fourth contribution to nomenclature of Cambrian Fossils. Smithsonian Miscellaneous Collections, 97: 1-43.

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

Other Links:

None

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

Micromitra burgessensis

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

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Paterinata (Order: Paterinida)
Remarks:

Micromitra belongs within the Family Paterinidae.

Species name: Micromitra burgessensis
Described by: Walcott
Description date: 1908
Etymology:

Micromitra – from the Greek mikros, “small,” and mitra, “turban.”

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: Holotype –USNM69646 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none to date. The Burgess Shale brachiopods, in particular from the Trilobite Beds on Mount Stephen, need to be re-examined (see also Brief history of research).

Other deposits: Numerous species, all from the Cambrian, are known worldwide.

Age & Localities:

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

The Walcott and Raymond Quarries on Fossil Ridge. Additional localities are known on Mount Field, Mount Stephen, and near Stanley Glacier.

History of Research:

Brief history of research:

Originally identified as Micromitra (Iphidella) pannula by Walcott (1908) from the Trilobite Beds on Mount Stephen (see also Walcott, 1912), it was redescribed as a new species by Resser (1938). Resser’s description fails to distinguish Micromitra burgessensis from any other species of the genus, it was based upon only a single valve, and it was not illustrated. The validity of this species is questionable and needs reassessment.

Description:

Morphology:

This species is the most ornamented of the Burgess Shale brachiopods. The shell was originally mineralized. It has pronounced growth lines and fine raised lines which cut obliquely across the shell. The intersection between the different lines creates small diamonds on the surface of the shell. The valves are subcircular with the hinge nearly straight. Perhaps the most striking of the preserved features of this animal are long and slender bristles (setae) which extend far beyond the margins of the shell. These would have been attached to the edge of the mantle along both the dorsal and ventral valves.

Abundance:

Micromitra burgessensis is relatively common in the Walcott Quarry but overall represents a small fraction of the fauna (<0.3%) (Caron and Jackson, 2008). This species is also present in the Raymond Quarry on Fossil Ridge.

Maximum Size:
10 mm

Ecology:

Ecological Interpretations:

Many specimens of Micromitra burgessensis are preserved attached to spicules of the sponge Pirania, suggesting that this species was epibenthic, supported 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 might have also helped reduce mud particles.

References:

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

RESSER, C. E. 1938. Fourth contribution to nomenclature of Cambrian Fossils. Smithsonian Miscellaneous Collections, 97: 1-43.

WALCOTT, C. 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.

Other Links:

None

Lingulella waptaensis

Reconstruction of Lingulella waptaensis.

© Marianne Collins

Taxonomy:

Class: Lingulata (Order: Lingulida)
Remarks:

Lingulella belongs within the Family Obolidae.

Species name: Lingulella waptaensis
Described by: Walcott
Description date: 1924
Etymology:

Lingulella – from the Latin lingua, “tongue,” and ellus, “diminutive.”

waptaensis – from Wapta Moutain (2,778 m), just north of the Walcott Quarry, in British Columbia, Canada.

Type Specimens: Syntypes –USNM69822-69824 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: None to date. The Burgess Shale brachiopods in particular from the Trilobite Beds on Mount Stephen need to be re-examined (see also Brief history of research).

Other deposits: Hundreds of species have been assigned to the genus Lingulella.

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:

Lingulella waptaensis was only cursorily described by Walcott (1924). At least another possible related form is known from the Trilobite Beds – originally described as Lingulella mcconnelli (Walcott, 1889; Matthew, 1902) and later renamed Obolus mconnelli (Walcott, 1908, 1912). Sutton et al. (2000) revised the diagnosis of Lingulella, restricting the concept of what had become a ‘trashcan’ genus for any similar elongate forms (called “obolids”). Consequently, many of the hundreds of species assigned to Lingulella no longer fit the diagnosis. As such, ‘Lingulella’ waptaensis needs to be re-examined to determine whether it conforms to the current concept of the genus. Shell structures and the first specimens with pedicles preserved have recently been described from the Burgess Shale (Pettersson et al., 2010).

Description:

Morphology:

Lingulella waptaensis is elongate and suboval in outline. The valves are weakly biconvex and smooth with the exception of growth lines. The visceral areas are weakly impressed to the interior of the shell and difficult to study in details. The pedicle is slender and protrudes between the valves. It is at least three times the length of the valves and is often twisted and wrinkled. The shell was originally mineralized.

Abundance:

Lingulella waptaensis is known from several hundred specimens in the Walcott Quarry but overall represents a small fraction of the fauna (<0.7%) (Caron and Jackson, 2008)

Maximum Size:
10 mm

Ecology:

Ecological Interpretations:

Like another comparable brachiopod from the Burgess Shale, Acanthotretella spinosa, the long, thin pedicle and overall shell shape of Lingulella waptaensis probably precludes an infaunal habit. The pedicle was likely able to maintain the shell in an upright position well above the sediment-water interface. Extraction of food particles from the water would have been possible thanks to a filter-feeding apparatus (located between the shells) called a lophophore.

References:

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

MATTHEW, G. F. 1902. Notes on Cambrian Faunas: Cambrian Brachiopoda and Mollusca of Mt. Stephen, B.C. with the description of a new species of Metoptoma. Transactions of the Royal Society of Canada, 4: 93-112.

PETTERSSON, S., L. E. HOLMER AND J.-B. CARON. 2010. First record of a pediculate linguloid from the Middle Cambrian Burgess Shale. Acta Zoologica, 91: 150-162.

SUTTON, M. D., M. G. BASSET AND L. CHERNS. 2000. The type species of Lingulella (Cambrian Brachiopoda). Journal of Paleontology, 74: 426-438.

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. 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 Brachioda. Cambrian Geology and Paleontology IV. Smithsonian Miscellaneous Collections, 67: 477-554.

Other Links:

Acrothyra gregaria

3D animation of Acrothyra gregaria and other brachiopods (Diraphora bellicostataMicromitra burgessensisNisusia burgessensis, and Paterina zenobia).

ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM

Taxonomy:

Class: Lingulata (Order: Acrotretida)
Remarks:

Acrothyra belongs within the Family Acrotretidae.

Species name: Acrothyra gregaria
Described by: Walcott
Description date: 1924
Etymology:

Acrothyra – from the Greek akros, “at the extremity,” and thyra, “door.”

gregaria – from the Latin gregaria, “in clusters,” and thyra, “door.”

Type Specimens: Syntypes –USNM69825-69828 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
Other species:

Burgess Shale and vicinity: None to date. At least one possible related form is known from the Trilobite Beds – originally described as Acrotreta gemma var. depressa (Walcott, 1889) and later renamed Acrotreta depressa (Matthew, 1902; Walcott, 1908, 1912). 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: Many species of Acrothyra are known in the Middle Cambrian of North America, Russia and possibly Europe.

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:

Acrothyra gregaria has not been studied since its original description by Walcott in 1924. Walcott’s description is cursory, inadequately diagnosing the specimen, and no primary types were designated. The species needs to be redescribed.

Description:

Morphology:

Dorsal and ventral valves measuring up to 2 mm in length, with a long medium ridge (or septum) on the dorsal valve. The shell was originally mineralized.

Abundance:

Acrothyra gregaria is known from several hundred specimens in the Walcott Quarry but overall represents a small fraction of the fauna (<0.5%) (Caron and Jackson, 2008).

Maximum Size:
2 mm

Ecology:

Ecological Interpretations:

Acrothyra most likely had a short pedicle by which it was attached to the substrate near the sediment-water interface, or raised on small organic material. As the species name indicates, many specimens would have lived together, filtering small food particles from the water with their filter-feeding apparatus (located between the valves) called a lophophore.

References:

MATTHEW, G. F. 1902. Notes on Cambrian Faunas: Cambrian Brachiopoda and Mollusca of Mt. Stephen, B.C. with the description of a new species of Metoptoma. Transactions of the Royal Society of Canada, 4: 93-112.

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. 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