Guemesia

Guemesia (named after Martín Miguel de Güemes, whose death bicentenary was in 2021) is a genus of abelisaurid dinosaur from the Late Cretaceous Los Blanquitos Formation of Salta Province, Argentina. The type and only species is Guemesia ochoai, known from a nearly complete braincase. It is one of the smallest abelisaurids currently known.^[1]

Guemesia Temporal range: Late Cretaceous ~72 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Drawing of Guemesia ochoai
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Family:	†Abelisauridae
Genus:	†Guemesia Agnolín et al., 2022
Species:	†G. ochoai
Binomial name
†Guemesia ochoai Agnolín et al., 2022

Discovery

The holotype of Guemesia, IBIGEO-P 103, is a small, nearly complete braincase. It was found in the Los Blanquitos Formation, in the Amblayo Valley of Salta Province, Argentina. The specimen was described in 2022 by Agnolín et al. as belonging to a new genus and species of abelisaurid dinosaur, and the first dinosaur of its kind known from the area.^[1]

Classification

Agnolín et al. place Guemesia as a derived abelisaurid within the clade Brachyrostra.^[1]

Abelisauridae	Spectrovenator Rugops Viavenator Majungasaurinae Rahiolisaurus Arcovenator Rajasaurus Indosaurus Majungasaurus Brachyrostra Skorpiovenator Niebla Llukalkan Ilokelesia Guemesia Ekrixinatosaurus Carnotaurinae Carnotaurus Aucasaurus Abelisaurus

Paleoecology

Guemesia is known from the Los Blanquitos Formation. The controversial tetanuran theropod Unquillosaurus is also known from this formation,^[2] as well as fossils of what may belong to a species of Titanosaurus.^[3][1]