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| Titanochampsa iorii Fachini, Godoy, Marsola, Montefeltro & Langer, 2022 Life reconstruction: Júlia d'Oliveira |
ABSTRACT
Most crocodyliforms of the Bauru Group were found in rocks of the Adamantina Formation, whereas the younger Marília Formation is almost devoid of such fossils. Here, we provide a detailed comparative description of MPMA 02–0005/87, a large skull roof found in Marília Formation deposits of the Monte Alto area, assigning it to a new crocodyliform. Despite its fragmentary nature and puzzling suit of characters, the new taxon possesses enough characters to reject its placement within Notosuchia, which is so far the only crocodyliform clade known from the Bauru Group. We tested its phylogenetic position with two data matrices, both of which recovered the new taxon within Neosuchia and Eusuchia. Although the material does not preserve any eusuchian synapomorphy, a neosuchian affinity is supported by: anterior extension of the meatal chamber covered by the squamosal; constricted flange of the posterior process of the postorbital; poorly developed posterolateral process of squamosal. Finally, the large size estimated for the specimen, ranging from 2.98 to 5.88 metres, coupled with its possible neosuchian affinity, suggests a possible semiaquatic behaviour, an ecology rarely explored by the predominantly terrestrial crocodyliforms of the Bauru Group.
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| Position of the preserved skull roof of Titanochampsa iorii on a hypothetical crocodyliform skull. Scale bar = 5 cm. |
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| Geological map of the Bauru Group in São Paulo state. The type location of MPMA 02-0005/87 is indicated by a red dot. |
CROCODYLOMORPHA Hay, 1930 (sensu Benton and Clark1988)
CROCODYLIFORMES Hay, 1930 (sensu Clark 1986)
MESOEUCROCODYLIA Whetstone and Whybrow 1983
Titanochampsa iorii gen. et sp. nov.
Etymology: The generic name congregates the latinised Greek words ‘titan’ (=large/brutal) and ‘champsa’ (= Titanochampsa ), in reference to the large size of the animal and also its previous identification as a titanosaur dinosaur. The specific epithet ‘iorii’ honours the Brazilian palaeontologist Fabiano V. Iori, due to his numerous contributions to the palaeontology of the Monte Alto region.
Holotype: MPMA 02–0005/87 (Figures 2–5), a partial cranial roof including frontal, parietal, supraoccipital, right postorbital, squamosal, quadrate, quadratojugal, and laterosphenoid.
Thiago S. Fachini, Pedro L. Godoy, Júlio C. A. Marsola, Felipe C. Montefeltro and Max C. Langer. 2022. A Large-sized Mesoeucrocodylian from the Late Cretaceous of Brazil with possible Neosuchian Affinities. Historical Biology: An International Journal of Paleobiology. DOI: 10.1080/08912963.2022.2122822
