A new crocodylomorph specimen from the Araripe Basin (Crato Member, Santana Formation), northeastern Brazil

Abstract

The fossil fauna of the Santana Formation (Early Cretaceous) comprises many distinct taxa, but crocodylomorphs are poorly understood. Here we describe a new specimen (MPSC-R1137) that consists of a complete hind limb found in the Crato Member, the basal section of the Santana Formation. Based on the characteristics of the fibula (e.g., pronounced variation of the shaft width) and length proportions of the femur and tibia, this specimen can be distinguished from Caririsuchus camposi and Araripesuchus gomesii, which are known from the Romualdo Member (the upper lithostratigraphic unit of the Santana Formation). The only crocodylomorph formally described from the Crato Member is Susisuchus anatoceps, whose holotype lacks elements of the hind limb. On the basis of a comparative anatomical study of the hind limb, which shows no similarities between MPSC-R1137 and other crocodylomorphs from the Araripe Basin, we tentatively classify this new specimen as cf. Susisuchus sp., and provide new anatomical information for this rather derived crocodylomorph.

Description of a new specimen ofSusisuchus anatoceps(Crocodylomorpha: Mesoeucrocodylia) from the Crato Formation (Santana Group) with comments on Neosuchia

“…The best Cretaceous neosuchian material from Brazil is from the Crato Formation Lagerstätte : Susisuchus anatoceps , and other related material (Salisbury et al ., 2003; Frey & Salisbury, 2007; Figueiredo & Kellner, 2009). Further susisuchid material was recorded from the Lima‐Campos Basin (Early Cretaceous) of north‐east Brazil (Fortier & Schultz, 2009).…”

“…Character 33 (proportion between forelimbs and hind limbs) was coded as 0 with both limbs approximately equal in length. The specimen regarded by Figueiredo & Kellner (2009) as cf. Susisuchus (MPSC‐R1137), which comprises hind limb remains, is clearly a juvenile of a very small size even when compared with MPSC‐R1136 and the holotype of Susisuchus anatoceps .…”

“…Referred specimens: MPSC‐R1136 – partially articulated postcranial remains comprising cervical and dorsal vertebrae; bones of the pectoral girdle including the right forelimb; and osteoderms from the dorsal shield. MPSC‐R1137 – a complete partially articulated right hind limb, including femur, tibia, fibula, and pes (Figueiredo & Kellner, 2009).…”

New evidence of feathers in the Crato Formation supporting a reappraisal on the presence of Aves

“…In addition, ostracods, conchostracans (Carvalho and Viana 1993), fishes (e.g. Santos 1947, Castro-Leal andBrito 2004), amphibians (Kellner and Campos 1986, CastroLeal and Brito 2006, Castro-Leal et al 2007, Baez et al 2009), pterosaurs (Frey and Martill 1994, Campos and Kellner 1997, Sayão and Kellner 1998, Witton 2008 and crocodylomorphs (Salisbury et al 2003, Figueiredo andKellner 2009), as well as a rich flora of pollen, spores and plant fragments, are present. Lastly, several feathers have been collected and described (Martins-Neto and Kellner 1988, Kellner et al 1991, 1994, Martill and Filgueira 1994, Martill and Davis 1998, Kellner 2002, some of which even show the presence of colored patterns (Martill and Frey 1995, Kellner et al 1999, Naish et al 2007, Vinther et al 2008, 2010.…”

A new angiosperm from the Crato Formation (Araripe Basin, Brazil) and comments on the Early Cretaceous Monocotyledons

“…The fossiliferous record of this formation is abundant and diverse (Mabesoone and Tinoco 1973). The fossils are found in laminated limestones of lacustrine environment, developed under tropical, arid and semi-arid climatic conditions, with long intervals of dry weather and periodic precipitation Kellner and Campos 1986, Baez et al 2009), pterosaurs (Frey and Martill 1994, Sayão and Kellner 2000, Kellner and Campos 2007, Witton 2008, Pinheiro et al 2011, crocodylomorphs (Salisbury et al 2003, Figueiredo andKellner 2009) and feathers (e.g. Sayão et al 2011).…”