taxonID	type	format	identifier	references	title	description	created	creator	contributor	publisher	audience	source	license	rightsHolder	datasetID
03FD87F90B2FFB6EFCA6F8B5FADDF974.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/14846149/files/figure.png	https://doi.org/10.5281/zenodo.14846149	FIG. 1. — Mesosaurus tenuidens Gervais, 1865 specimens showing the morphology of the “pygal-like” segment: A, GP-2E 653a, posterior region of presacral series, pelvic girdle and hind limbs, and anterior part of the tail showing only nine caudal vertebrae carrying ribs, which decrease in size posteriorly; B, GP-2E 674b showing aggregation of juvenile and adult individuals. The whole “pygal-like” segment (ten vertebrae) is preserved. Scale bars: A, 30 mm; B, 10 mm.	FIG. 1. — Mesosaurus tenuidens Gervais, 1865 specimens showing the morphology of the “pygal-like” segment: A, GP-2E 653a, posterior region of presacral series, pelvic girdle and hind limbs, and anterior part of the tail showing only nine caudal vertebrae carrying ribs, which decrease in size posteriorly; B, GP-2E 674b showing aggregation of juvenile and adult individuals. The whole “pygal-like” segment (ten vertebrae) is preserved. Scale bars: A, 30 mm; B, 10 mm.	2025-01-23	Piñeiro, Graciela;Ferigolo, Jorge;Farias, Brodsky Dantas Macedo de;Demarco, Pablo Núñez;Laurin, Michel		Zenodo	biologists	Piñeiro, Graciela;Ferigolo, Jorge;Farias, Brodsky Dantas Macedo de;Demarco, Pablo Núñez;Laurin, Michel			
03FD87F90B2FFB6EFCA6F8B5FADDF974.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/14846151/files/figure.png	https://doi.org/10.5281/zenodo.14846151	FIG. 2. — Mesosaurus tenuidens Gervais, 1865 from the Mangrullo Formation of Uruguay. Morphology of the last caudal vertebrae of the pygal-like segment: A, B, FC-DPV 2206; C, FC-DPV 2467; D, FC-DPV 2231. These specimens show the presence of transverse processes and associated ribs (yellow arrowheads), as well as a haemal arch (red arrowheads) in the preserved vertebrae. They must consequently be part of the last of the “pygal-like” series because the anterior portion of that segment lack chevrons, whereas in the postpygal vertebrae, transverse processes are very poorly developed, if at all. Scale bars: 10 mm.	FIG. 2. — Mesosaurus tenuidens Gervais, 1865 from the Mangrullo Formation of Uruguay. Morphology of the last caudal vertebrae of the pygal-like segment: A, B, FC-DPV 2206; C, FC-DPV 2467; D, FC-DPV 2231. These specimens show the presence of transverse processes and associated ribs (yellow arrowheads), as well as a haemal arch (red arrowheads) in the preserved vertebrae. They must consequently be part of the last of the “pygal-like” series because the anterior portion of that segment lack chevrons, whereas in the postpygal vertebrae, transverse processes are very poorly developed, if at all. Scale bars: 10 mm.	2025-01-23	Piñeiro, Graciela;Ferigolo, Jorge;Farias, Brodsky Dantas Macedo de;Demarco, Pablo Núñez;Laurin, Michel		Zenodo	biologists	Piñeiro, Graciela;Ferigolo, Jorge;Farias, Brodsky Dantas Macedo de;Demarco, Pablo Núñez;Laurin, Michel			
03FD87F90B2FFB6EFCA6F8B5FADDF974.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/14846155/files/figure.png	https://doi.org/10.5281/zenodo.14846155	FIG. 3. — Mesosaurus tenuidens Gervais, 1865 “fracture/suture lines” present in all the vertebrae forming the “postpygal” segment of the tail: A, SMNS 51560. Photograph of an almost complete skeleton of a subadult specimen showing the very long tail of mesosaurs,which exceeds the length of the skull plus the thoracic region. The end of the “pygal” segment and the beginning of the postpygal region (white arrows) is identified by the presence of vertebrae showing the centrum divided in two areas by a subcentral “fracture/suture line”; B, detailed view of the tail of SMNS 51560 with the outline of bones highlighted; C, interpretive drawing of B; the pygal segment (pys) and the limi with the postpygal vertebrae are delimited by bracket and arrow respectively, in red color. Scale bars: 30 mm.	FIG. 3. — Mesosaurus tenuidens Gervais, 1865 “fracture/suture lines” present in all the vertebrae forming the “postpygal” segment of the tail: A, SMNS 51560. Photograph of an almost complete skeleton of a subadult specimen showing the very long tail of mesosaurs,which exceeds the length of the skull plus the thoracic region. The end of the “pygal” segment and the beginning of the postpygal region (white arrows) is identified by the presence of vertebrae showing the centrum divided in two areas by a subcentral “fracture/suture line”; B, detailed view of the tail of SMNS 51560 with the outline of bones highlighted; C, interpretive drawing of B; the pygal segment (pys) and the limi with the postpygal vertebrae are delimited by bracket and arrow respectively, in red color. Scale bars: 30 mm.	2025-01-23	Piñeiro, Graciela;Ferigolo, Jorge;Farias, Brodsky Dantas Macedo de;Demarco, Pablo Núñez;Laurin, Michel		Zenodo	biologists	Piñeiro, Graciela;Ferigolo, Jorge;Farias, Brodsky Dantas Macedo de;Demarco, Pablo Núñez;Laurin, Michel			
