Gulosaurus

Gulosaurus is an extinct genus of basal grippidian ichthyopterygian known from the Early Triassic Vega-Phroso Siltstone Member of the Sulphur Mountain Formation of east-central British Columbia, Canada. Gulosaurus was first named by Robin S. Cuthbertson, Anthony P. Russell and Jason S. Anderson in 2013 and the type species is Gulosaurus helmi.[2] The name means 'Helm's wolverine lizard' and refers to the Wolverine Nordic and Mountain Society, who maintain the area around Wapiti Lake where it was found, and to Dr Charles Helm, who is a leading paleontologist around this same area.[3]

Gulosaurus Temporal range: Early Triassic, 251.3–247.2 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	†Grippidia
Genus:	†Gulosaurus Cuthbertson, Russell & Anderson, 2013
Type species
†Gulosaurus helmi Cuthbertson et al., 2013

Originally Gulosaurus was thought to be either Grippia longirostris or Parvinatator wapitiensis, but as the fossil was incomplete it was uncertain which. In 2013, the other half of the fossil, including its skull, was discovered and this proved it to be a new species entirely, closely related to Grippia and very similar.

Features

Overall, Gulosaurus was similar to Grippia. It was the same size, around 1.5 meters long, and much of the skeleton was the same, namely the ribs and centrum discovered. Also like Grippia, it had pentadactyl limbs rather than exhibiting polyphalangy, as many later ichthyopterygians did. Most of the flipper structure was very similar apart from the first metacarpal, which had a notched peripheral shaft in Gulosaurus but was lunate in Grippia. The skull of Gulosaurus was also very different to that of Grippia - it had cylindrical anterior teeth, although as no Grippia snouts have been discovered, it remains unknown if this was different. The skull also exhibited postfrontal-frontal contact at the rostral limit of the anterior margin of the supratemporal terrace.[2]

Phylogeny

Below is a cladogram modified from Cuthbertson et al., 2013.[2]

Ichthyopterygia

Parvinatator wapitiensis     Utatsusaurus hataii         Xinminosaurus catactes   Eoichthyosauria Grippidia   Grippia longirostris     Gulosaurus helmi     Ichthyosauria sensu Motani (1999)   Chaohusaurus geishanensis       Cymbospondylus     Mixosauria   Mixosaurus cornalianus     Phalarodon atavus       Toretocnemidae   Qianichthyosaurus zhoui     Toretocnemus californicus       Shastasauria   Shonisaurus popularis       Shastasaurus pacificus     Callawayia neoscapularis           Guizhouichthyosaurus tangae       Besanosaurus leptorhynchus       Californosaurus perrini     Parvipelvia

See also

• List of ichthyosaurs
• Timeline of ichthyosaur research

References

1. "Gulosaurus Cuthbertson et al. 2013". Paleobiology Database. Fossilworks. Retrieved 12 August 2017.
2. Cuthbertson, R. S.; Russell, A. P.; Anderson, J. S. (2013). "Cranial morphology and relationships of a new grippidian (Ichthyopterygia) from the Vega-Phroso Siltstone Member (Lower Triassic) of British Columbia, Canada". Journal of Vertebrate Paleontology. 33 (4): 831–847. doi:10.1080/02724634.2013.755989. S2CID 131501541.
3. "Doctor Dinosaur designation takes on new meaning | Tumbler Ridge News | News and Opinions for Tumbler Ridge". tumblerridgenews.com. Retrieved 2018-03-18.