Fused mid‐caudal vertebrae in the titanosaur Uberabatitan ribeiroi from the Late Cretaceous of Brazil and other bone lesions

Abstract

Bone pathology in the titanosaur dinosaur Uberabatitan ribeiroi from the Marília Formation (Bauru Group, Late Cretaceous) of Uberaba city (Minas Gerais State, Brazil) is analysed here. They include two fused procoelous mid‐caudal vertebrae (CPPLIP‐1020) and a haemal arch (CPPLIP‐1006) of the middle section of the tail with a healing fracture callus. The analyses of the caudal vertebrae CPPLIP‐1020 of Uberabatitan permit us to recognize the following signs, based on CT scan and external macroscopic observations: (1) ossified longitudinal tendons; (2) likely ossified intervertebral disc, producing fused vertebral bodies; (3) fused right zygapophyseal process with a laterally developed osteophyte affecting this joint; (4) osteophytes and exostoses at different portions of the vertebrae; (5) cloacae, bone erosion and likely internal infection. According to all the processes observed in these caudals, we could not discard at least two possibilities for the diagnosis of the fused vertebrae. It could be the result of a spondyloarthropathy process (considering most of the observed signs) or possibly have been associated with an infection (e.g. discospondylitis/infections spondylitis or septic arthritis). The bone lesion record in Uberabatitan ribeiroi from the Late Cretaceous of Brazil increases the range of study of titanosaur dinosaurs, which although have a large fossil record, have few pathological studies.

The first evidence of osteomyelitis in a sauropod dinosaur

“…Relative to the extent of the fossil record, pathological specimens have generally been infrequently recognized, and involvement of sauropods, even less reported (Hatcher ; Holland ; Rothschild & Berman ; Rothschild & Molnar ; Lovelace ; Martinelli et al . ). We believe that pathology in dinosaurs is more frequent than published and that these abnormalities are usually unnoticed or underestimated.…”

“…More recently, Martinelli et al . () reported fused vertebrae in the Brazilian titanosaur Uberabatitan ribeiroi , interpreted either as the result of a spondyloarthropathy process or an infection. Osteomyelitis, however, has not been previously reported in sauropod dinosaurs.…”

Osseous anomalies of the cryptobranchid <i>Eoscapherpeton asiaticum</i> (Amphibia: Caudata) from the Late Cretaceous of Uzbekistan

“…14-15) could be evidence of frequent occurrence of hind limb injuries in Eoscapherpeton asiaticum. In modern cryptobranchids such as Cryptobranchus, limb injuries are the most common physical abnormalities in wild populations (Miller and Miller, 2005). The proposed main cause of limb injuries in Cryptobranchus is intraspecific ag- gression during the reproductive season (e.g., defending of nesting sites), because fresh injuries were found only during the reproductive season (namely in August and September) (Hiler et al, 2005;Miller and Miller, 2005).…”

“…In modern cryptobranchids such as Cryptobranchus, limb injuries are the most common physical abnormalities in wild populations (Miller and Miller, 2005). The proposed main cause of limb injuries in Cryptobranchus is intraspecific ag- gression during the reproductive season (e.g., defending of nesting sites), because fresh injuries were found only during the reproductive season (namely in August and September) (Hiler et al, 2005;Miller and Miller, 2005). Taking into account the phylogenetic position of Eoscapherpeton as a member of the cryptobranchid clade and their aquatic lifestyle (see Skutschas, 2009Skutschas, , 2013, the reason for the frequent occurrence of hind limb injuries in E. asiaticum could be the same (intraspecific aggression during reproductive season), and this behavioral element could have appeared early in the evolution of cryptobranchids, i.e., at least in the Late Cretaceous.…”

“…The study of paleopathology offers an effective tool for understanding some aspects of vertebrate paleobiology, including lifestyle and behavior (e.g., Hanna, 2002;Martinelli et al, 2015), as well as reaction of the skeletal tissues to diseases and injuries (traumas) through the time (Rothschild and Tanke 1991;Rothschild and Martin, 2006;Waldron, 2009). Despite numerous paleopathological studies of different tetrapods (e.g., dinosaurs, crocodiles), paleopathologies among fossil members of modern groups of amphibians (i.e., lissamphibians: frogs, salamanders and caecilians) are poorly documented (Rothschild, 2012;Rothschild and Laub, 2013).…”