NUEVA ESPECIE DE TORTUGA TERRESTRE GIGANTE DEL GÉNERO CHELONOIDIS FITZINGER, 1835 (CRYPTODIRA: TESTUDINIDAE), DEL MIEMBRO INFERIOR DE LA FORMACIÓN TOROPÍ/ YUPOÍ (PLEISTOCENO TARDÍO/ LUJANENSE), BELLA VISTA, CORRIENTES, ARGENTINA

ZACARIAS, G.; DE LA FUENTE, M. S; FERNÁNDEZ, S.; ZURITA, A. E

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2013 vol. 50 p. 298 - 318

0002-7014

NEW SPECIES OF GIANT TORTOISE OF THE GENUS CHELONOIDIS FITZINGER, 1835 (CRYPTODIRA: TESTUDINIDAE),FROM THE LOWER MEMBER OF THE TOROPÍ/ YUPOÍ FORMATION (LATE PLEISTOCENE/ LUJANIAN),BELLA VISTA, CORRIENTES, ARGENTINA. A new species of giant tortoise from the upper section of the lower member of Toropí/Yupoí Formation (late Pleistocene, 58-22 ka) is described. The holotype of this new species was recovered at Arroyo Toropí (10 km southfrom Bella Vista city, Corrientes Province, Argentina). The presence of pectoral scales in the plastron narrower in midline and antero-posteriorly expanded towards the marginal scutes, allow us to assign this tortoise to the genus Chelonoidis Fitzinger. The non parallel lateral margins,the peripheral bones lobed in the bridge, the elliptical depression on both sides of peripheral bones III, and a sub- rhomboidal entoplastron proximally broadening, with distal projections covering the pectoral scales, allow us to recognize a new species, Chelonoidis lutzae sp. nov. The strict consensus tree of the phylogenetic analysis of Chelonoidis shows a polytomy among Ch. lutzae sp. nov., Ch. gallardoi (Rovereto), Ch. australis (Moreno), and the extant and extinct species assigned to carbonaria and chilensis groups. The carbonaria group includes Ch. denticulata (Linnaeus) and another clade formed by Ch. carbonaria (Spix) and Ch. hesterna (Auffenberg). The chilensis group, includes two subclades, one composed by Ch. chilensis (Gray), Ch. petersi (Freiberg) and Ch. nigra (Quoy and Gaimard), and another formed by YPFBPAL 0932 and Ch. gringorum (Simpson). Using the pruned tree option of TNT an extinct giant continental tortoise clade (Ch. lutzae sp. nov. and Ch. australis) is recovered, clearly differentiated from the giant Galápagos tortoises.