Fossil Gallery

Home > Fossil Gallery > Scolecofurca

Scolecofurca rara

A worm with a fork-like front end

Image of Scolecofurca rara.

Get Adobe Flash player

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

Media 1 of 1 for Scolecofurca rara Photo

Taxonomy

Kingdom:

Animalia

Phylum:

Priapulida

Class:

Unranked clade (stem group priapulids)

Affinity:

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.

Back to top

Age

Period:

Middle Cambrian, Bathyuriscus-Elrathina Zone (approximately 505 million years ago).

Back to top

Localities

Principal localities:

The Raymond Quarry on Fossil Ridge.

Back to top

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).

Back to top

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

Back to top

Ecology

Life habits:

Endobenthic, mobile

Feeding strategies:

Unknown

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.

Back to top

References

Bibliography:

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

Back to top