Baisesaurus

Baisesaurus (meaning "Baise lizard") is an extinct genus of ichthyosauromorph from the early Triassic (Spathian) Luolou Formation of Guangxi, China. The genus contains a single species, B. robustus, known from a partial postcranial skeleton.^[1]

Baisesaurus Temporal range: Early Triassic, 250 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	†Ichthyosauromorpha
Genus:	†Baisesaurus Ren et al., 2022
Species:	†B. robustus
Binomial name
†Baisesaurus robustus Ren et al., 2022

Discovery and naming

The Baisesaurus holotype specimen, CUGW VH107, was discovered in 2018 in a layer of the Luolou Formation in the Nanpanjiang Basin of Zhebao Township, Longlin County, Baise, Guangxi region, China. The specimen consists of assorted ribs, gastralia, a limb element (likely a radius), 12 vertebral centra, and seven neural arches.

In 2022, Ren et al. described Baisesaurus robustus, a new genus and species of basal ichthyosauromorph. The generic name, "Baisesaurus", combines a reference to the type locality in Baise, China, with the Greek "saurus", meaning "lizard". The specific name, "robustus", means "robust".^[1]

Description

Baisesaurus was likely at least 3 m (9.8 ft) long. It was more similar to Utatsusaurus than to any other ichthyosauromorph, with similar size and anatomical traits. It can be inferred from related animals that Baisesaurus was a strong swimmer with long, compact forelimb bones.^[1]

Classification

Baisesaurus likely represents a basal member of the clade Ichthyosauromorpha. The describing authors explain that it may represent a member of the Ichthyopterygia. However, such a classification is highly tentative.^[1]