Metaspriggina

Metaspriggina Temporal range: Burgess Shale PreЄ Є O S D C P T J K Pg N ↓
An artist's concept of Metaspriggina based on Conway Morris, Caron.
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Family:	Metaspriggiidae
Genus:	Metaspriggina
Species:	M. walcotti
Binomial name
Metaspriggina walcotti

Metaspriggina is a genus of chordate initially known from two specimens in the Middle Cambrian Burgess Shale and 44 specimens found in 2012 at the Marble Canyon bed in Kootenay National Park.

Whilst named after the Ediacaran organism Spriggina, later work has shown the two to be unrelated.Metaspriggina is considered to represent a primitive chordate, possibly transitional between cephalochordates and the earliest vertebrates, albeit this has been questioned because it seems to possess most of the characteristics attributed to craniates. It lacked fins and it had a weakly developed cranium, but it did possess two well-developed upward-facing eyes with nostrils behind them.

Metaspriggina also possessed a , along with seven pairs of pharyngeal bars, possibly made of cartilage. Surprisingly they were not formed from a singular bone, but they were formed of multiple separate pairs of bones, along with first two of them that were enlarged compared to the others and that seemed to not support any gills, all of these characteristics suggesting a "distant link to gnathostomatans". The largest specimens are 10 centimetres (3.9 in) in length. Originally believed to be free-swimming but occasionally found on the sea floor, the fossils from Marble Canyon showing the presence of eyes and their placement suggests it lived as a filter-feeder swimming above the sea floor.

The exceptional preservation at Marble Canyon also preserved muscle detail, showing that the animal moved with a side-to-side swimming motion. In Metaspriggina the myomeral configuration has an additional ventral chevron, and a clear dorsal bend which defines a W-shaped arrangement that is directly comparable to fish.