Maxakalisaurus

Discovery and naming

Between 1998 and 2002, over four field seasons, the National Museum of Brazil dug up a partial titanosaur skeleton beside the Campina Verde - Prata road, 45 kilometers west of Prata in Minas Gerais. In 2006, Alexander W. A. Kellner and his team named the find a new genus and species: Maxakalisaurus topai. The genus name pays tribute to the Maxakali people, an indigenous group from that area, while the species name comes from their deity Topa. The holotype, labeled MN 5013-V, once stored at the National Museum, consisted of a fragmentary right maxilla with teeth, twelve cervical vertebrae plus some cervical ribs, seven dorsal vertebrae and ribs, a sacral neural spine and centrum, six caudal vertebrae, several haemal arches, parts of the scapulae, both sternal plates, a piece of the left ischium, both humeri, two metacarpals, part of a fibula, an osteoderm, and assorted unidentified fragments.

Two extra sternal plates and part of a third scapula found at the same site likely belong to a second animal. Some bones came from an adult, others from a subadult. Later, a partial dentary and teeth from the same locality were also assigned to M. topai. During the National Museum fire on 2 September 2018, many holotype elements were destroyed, but several survived and were retrieved.

Description

Maxakalisaurus was a titanosaur of average size, reaching about 12.1 meters in length and weighing around 5 tons. It possessed a long neck and tail, along with ridged teeth that were rare among sauropods. Living roughly 80 million years ago, it carried osteoderms, a common feature among titanosaurs. South America’s lack of major competition allowed sauropods there to develop more unusual traits and greater diversity.