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| Labrujasuchus expectatus Turner, Kernan, Laing, Pritchard, Stocker, Irmis, Smith, Werning & Nesbitt, 2026 Artwork: Jorge Gonzalez/NHMLAC Dinosaur Institute |
ABSTRACT
Bipedal shuvosaurid archosaurs were present for much of the Late Triassic Period. The clade is particularly diverse in Upper Triassic assemblages in the western U.S.A. Isolated bones are easily differentiated from contemporary archosaurs, but the two named North American species, Shuvosaurus inexpectatus and Effigia okeeffeae, display remarkably similar skeletons. Here we describe a new shuvosaurid species, Labrujasuchus expectatus, gen. et sp. nov., from the middle Norian (∼212 Ma) Hayden Quarry of northern New Mexico, U.S.A., located within the Petrified Forest Member of the Chinle Formation, that fills the temporal gap between the two species. The holotype consists of a partial skeleton, with additional shuvosaurid material from the Hayden Quarry likely pertaining to this taxon. This taxon is distinguished by four autapomorphies and assignable to Shuvosauridae based on a deep fossa present on the posterodorsal edge of the coracoid, the proximal portion of the humerus less than twice the width of the midshaft, the anteromedial tuber of the femur large and ‘hooked’ posteriorly, and a ventrally descended posterolateral portion of the femoral head. Recent Bayesian estimates of archosaur phylogeny and divergence times suggested a Middle Triassic split for Shuvosauridae as well as a decrease in the rate of morphological evolution for the clade relative to that of other archosaurs. The anatomical similarity of L. expectatus with other shuvosaurids is consistent with these estimated low rates, and the long gaps in the fossil record for the clade suggest that much of their evolutionary history remains to be sampled.
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| Reconstruction of Labrujasuchus expectatus, a new species of Shuvosauridae from Late Triassic rocks of Ghost Ranch, New Mexico. Artwork: Jorge Gonzalez/NHMLAC Dinosaur Institute |
SYSTEMATIC PALEONTOLOGY
ARCHOSAURIA Cope, 1870 (sensu Gauthier & Padian, 1985)
SUCHIA Krebs, 1974 (sensu Benton & Clark 1988)
SHUVOSAURIDAE Chatterjee, 1993 (sensu Nesbitt, 2011)
LABRUJASUCHUS gen. nov.
Type Species—Labrujasuchus expectatus
Etymology—The generic name Labrujasuchus (“la-broo-ha-soo-kus”) is derived from “Ranchos de los Brujos,” Ranch of the Witches, an old Spanish name for the Ghost Ranch area, and the Greek word Σοῦχος (suchus) meaning “crocodile.” It is masculine in gender.
LABRUJASUCHUS EXPECTATUS sp. nov.
Etymology—From the Latin “expectatus” for expected or awaited.
The species name is based on the anticipated nature of a shuvosaurid discovery at the Hayden Quarry.
Alan H. Turner, Ciara E. Kernan, Adam Laing, Adam C. Pritchard, Michelle R. Stocker, Randall B. Irmis, Nathan D. Smith, Sarah Werning and Sterling J. Nesbitt. 2026. A New shuvosaurid (Archosauria, Poposauroidea) from the Late Triassic (Norian) Hayden Quarry of New Mexico, U.S.A. Journal of Vertebrate Paleontology. e2618182 DOI: doi.org/10.1080/02724634.2026.2618182 [26 May 2026]
