MADTSOIIDAE, Hoffstetter, 1961

Albino, Adriana María, 2000, New record of snakes from the Cretaceous of Patagonia (Argentina), Geodiversitas 22 (2), pp. 247-253 : 250

Family? MADTSOIIDAE

MATERIAL EXAMINED. — MPEF-PV 641, MPEF- PV 644 and MPEF-PV 645, incomplete vertebrae.

REMARKS

The parazygantral foramina are not visible in these specimens because the postzygapophyses are broken, therefore the remains are tentatively referred to madtsoiids due to the general constitution and the absence of prezygapophysial processes. MPEF-PV 641 is an incomplete vertebra characterized by its large size, wide neural arch, short and anteriorly widened vertebral centrum, small neural canal, thick zygosphene, prezygapophyses inclined above horizontal, prezygapophysial processes absent, large and rounded cotyle, lateral, subcentral and paracotylar foramina present, synapophyses located low from the centrum, and haemal keel developed. MPEF-PV 645 is a large fragment with the right prezygapophysis and part of the right postzygapophysis. It is attributed to the same taxon as MPEF-PV 641 specimen. Its centrum is wide, short and anteriorly widened, with developed haemal keel, prezygapophysial process absent and a very small paracotylar foramen on the right side of the large cotyle. Both MPEF-PV 641 and MPEF-PV 645 vertebrae are very different to those of other cretaceous madtsoiids of Patagonia. MPEF-PV 644 is a left prezygapophysis characterized by the absence of prezygapophysial process and the presence of paracotylar foramen.