Macrocephalosaurus
genus of rhynchosaurs
Macrocephalosaurus is a genus of rhynchosaurs (beaked, archosaur-like reptiles) from the Late Triassic period (Carnian stage) of southern Brazil. It contains a single species, Macrocephalosaurus mariensis. Although usually synonymized with Hyperodapedon (as the species Hyperodapedon mariensis), some cladistic analyses have called this synonymy into question.
Classification
The type species of Macrocephalosaurus, M. mariensis, was described in 1933 by Jaci Antonio Louzada Tupi Caldas on the basis of MCN 1867, a complete specimen from the upper member of the Santa Maria Formation in Rio Grande Do Sul State, southern Brazil. The skeleton was transferred to another museum in the mid-1950s, and as of 1998 only the skull and front part of the torso have been recovered; the rest of the skeleton is presumed lost. Langer (1996, 1998) regarded Macrocephalosaurus mariensis as a probable junior synonym of Hyperodapedon huxleyi, synonymizing Macrocephalosaurus with Hyperodapedon.
Nevertheless, Langer and Schultz (2000) listed M. mariensis as a valid species within Hyperodapedon, as H. mariensis. Mukherjee and Ray (2014) followed this interpretation. In their cladistic analysis of the newly described taxon Beesiiwo, Fitch et al. (2023) recovered Macrocephalosaurus as more closely related to Supradapedon and Teyumbaita rather than Hyperodapedon gordoni (the type species of Hyperodapedon) or Oryctorhynchus.
This brief starts where responsible research should: with the source description of “Macrocephalosaurus” as genus of rhynchosaurs. Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the science & nature register because the source frames it as genus of rhynchosaurs. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Stable identifiers, scientific names and standards terminology offer the best bridge between this overview and specialist evidence. The source revision retrieved here is dated Sep 20, 2026. The linked authority identifier is Q117661585. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1933, 1867, 1998 and 1996.
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This entry incorporates text from “Macrocephalosaurus” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.