Shastasauridae

Shastasauridae Temporal range: Triassic
Skeleton of Shastasaurus sikanniensis
Scale diagram of Shonisaurus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	†Ichthyosauria
Node:	†Merriamosauria Motani, 1999
Family:	†Shastasauridae Merriam, 1895
Genera
†Besanosaurus? †Himalayasaurus †Ichthyotitan? †Guanlingsaurus †Guizhouichthyosaurus? †Shonisaurus †Shastasaurus

Shastasauridae is an extinct

Shastasauridae was named by American paleontologist

Shastasaurids as typically defined have elongate bodies, with over 55 presacral vertebrae.^[6] They were the largest ichthyosaurs, with even some of the smaller species like Guanlingsaurus measuring over 8 metres (26 ft) in length.^[7] One of the largest specimens was discovered from England in May 2016,^[8] when researcher and fossil collector Paul de la Salle discovered a partial jawbone measuring 96 centimeters (3.15 ft) long which was catalogued as BRSMG Cg2488, also referred to as the Lilstock specimen. In 2018, Dean Lomax, de la Salle, Judy Massare, and Ramues Gallois identified the Lilstock specimen as a shastasaurid. While its incompleteness made the size of the animal difficult to suggest, it clearly was very large. Using Shonisaurus sikanniensis as a model, the researchers estimated the ichthyosaur to have been 26 meters (85 ft) long, nearly the size of a blue whale. Scaling based on Besanosaurus, however, found a shorter length estimate of 22 meters (72 ft).^[9] In 2024, the Lilstock specimen was referred to the newly described species Ichthyotitan, with a length estimate of up to 25 meters (82 ft).^[2]

Feeding habits

Unlike other

Although older studies have suggested that shastasaurids were suction-feeders, current research indicates that the jaws of shastasaurid ichthyosaurs do not fit the suction-feeding profile, since their short and narrow hyoid bones are unsuitable to withstand impact forces for such kind of feeding,[12] and since some species like Shonisaurus had robust sectorial teeth with gut contents of mollusk shells and vertebrates.^[13][11]

References