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| Patagoniaemys aeschyli Agnolin, Rolando, Sterli, Chimento, Novas & Muñoz, 2026 |
Meiolaniformes are a group of chelonians including the famous horned-turtles Niolamia argentina (Patagonia) and Meiolania platyceps (Australia). In South America, the Late Cretaceous meiolaniforms are represented by two named taxa: Patagoniaemys gasparinae coming from Campanian–Maastrichtian beds of the La Colonia Formation, Chubut province, and Trapalcochelys sulcata from the Campanian–Maastrichtian beds of the Allen Formation, Río Negro Province. The aim of the present contribution is to describe a new meiolaniform chelonian coming from the Upper Cretaceous (Maastrichtian) Los Alamitos Formation, at Río Negro Province, Argentina. The material is represented by a partial basicranium, incomplete carapace and fragmentary postcranial bones (MPMIK 1839/P/33) belonging to a new species Patagoniaemys aeschyli. To this new species we refer all the material previously referred as indeterminate meiolaniid, meiolaniform and cf. Niolamia sp., coming from the same site and locality, and described by different authors since the 1980s. This new species differs from the type species P. gasparinae, particularly by the presence of longitudinal ridges in the nuchal bone. We also include brief comments about meiolaniform palaeobiogeography and the impact of K/Pg extinction event in Patagonian chelonians.
Key words: Testudinata, Meiolaniformes, Los Alamitos Formation, Maastrichtian, Cretaceous, Patagonia, Argentina.
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| Meiolaniform turtle Patagoniaemys aeschyli sp. nov. holotype (MPMIK 1839/P/33); Cerro Cuadrado locality, Argentina, Los Alamitos Formation Maastrichtian (Upper Cretaceous). A. Carapace; anterior border in dorsal (A1, A2) and ventral (A3, A4) views, detail of the anterior margin in ventral view (A7, A8), showing the presence of longitudinal ridges that characterize the new species (light grey, nuchal bone; dark grey, broken surfaces). B. Left hyoplastron fragment Scale bars 100 mm. |
Testudinata Klein, 1760
Meiolaniformes Sterli & de la Fuente, 2013
Genus Patagoniaemys Sterli & de la Fuente, 2011a
Type species: Patagoniaemys gasparinae Sterli & de la Fuente, 2011a;
Chubut Province, Argentina, Campanian–Maastrichtian.
Chubut Province, Argentina, Campanian–Maastrichtian.
Patagoniaemys aeschyli sp. nov.
Diagnosis.—Large chelonian (maximum anterior carapace width about 60 cm, maximum inferred carapace length 80 cm). Referable to meiolaniforms by several features, namely the presence of small pits and grooves ornamenting carapace bones, anteriorly curved grooves among marginal scutes, opisthocoelous caudal vertebrae, and carapace-plastron connection through ligaments (Gaffney 1996; Hirayama et al. 2000; Sterli and de la Fuente 2013; Sterli et al. 2013). It is referred to Patagoniaemys by having a basioccipital with well-developed basal tubera with a concave surface between them, posteriorly flat occipital condyle, a shallowly notched anterior carapace margin, presence of a thickened bump on ...
Etymology: In reference to Aeschylus (525–455 BC), an ancient Greek writer often described as the father of tragedy. During a visit to the city of Gela (Italy), he was killed outside the city by a tortoise dropped by an eagle, which had mistaken his bald head for a rock suitable for shattering the shell.
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| the excavation work at the Los Alamitos Formation southwest of Cerro Cuadrado. |
Federico L. Agnolin, Mauro Aranciaga Rolando, Juliana Sterli, Nicolás R. Chimento, Fernando E. Novas, and Gonzalo L. Muñoz. 2026. A New meiolaniform Turtle from the Maastrichtian of Northern Patagonia, Argentina. Acta Palaeontologica Polonica. 71(1); 173-184. DOI: doi.org/10.4202/app.01268.2025
DESCUBREN UNA TORTUGA GIGANTE DEL FIN DE LA ERA DE LOS DINOSAURIOS EN PATAGONIA