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| Ahshislesaurus wimani Dalman, Jasinski, Malinzak, Malinzak, Lucas, Kundrát, Fiorillo, 2025 Artwork by Sergey Krasovskiy |
A new saurolophine hadrosaurid dinosaur, Ahshislesaurus wimani gen et sp. nov., from the lower Hunter Wash Member of the lower Kirtland Formation (~75.02 Ma) of New Mexico is described. The specimen was briefly described before and referred to the stratigraphically younger Kritosaurus navajovius, which is known from the De-na-zin Member (~73.83–73.49 Ma) of the uppermost Kirtland Formation. The holotype of A. wimani consists of an incomplete diagnostic skull, several isolated cranial elements including the right jugal, quadrate, dentary, and surangular, and a series of articulated cervical vertebrae. In addition to the holotype of A. wimani, several specimens from the same strata may also belong to this newly identified species, including a well-preserved left dentary and a partial skeleton, as well as two humeri, one belonging to a large adult and the other to a juvenile. The skull of A. wimani preserves several taxonomically informative characters that show close affinities with the stratigraphically younger Naashoibitosaurus ostromi from the De-na-zin Member. Together with Naashoibitosaurus, Ahshislesaurus forms a potentially novel clade of flat-headed saurolophine hadrosaurids. This clade suggests the saurolophines were a taxonomically diverse group, which, during the last 20 million years of the Cretaceous, were among the dominant herbivorous dinosaurs in southern Laramidia. Recognition of a new hadrosaurid species from New Mexico also provides further evidence for latitudinal variation in the hadrosaurid fauna during the Late Cretaceous in Laramidia.
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| Skeleton reconstruction of Ahshislesaurus wimani gen. et sp. nov., (USNM VP-8629), holotype skull. This includessome of the postcranial specimens from the lower Hunter Wash Member (Kirtland Formation) that may not represent this newspecies, including a postcranial skeleton (NMMNH P-25057); left scapula (NMMNH P-RMS 2013-7); left humerus (NMMNHP-31928); and right isolated ulna (NMMNH P-32885). |
SYSTEMATIC PALEONTOLOGY
DINOSAURIA Owen, 1842
ORNITHISCHIA Seeley, 1887
ORNITHOPODA Marsh, 1881
IGUANODONTIA Dollo, 1888
HADROSAURIA von Huene, 1956
HADROSAURIDAE Cope, 1870
SAUROLOPHINAE Brown, 1914
Ahshislesaurus, new genus
Etymology: The genus name Ahshislesaurus is from the Ah-shi-sle-pah Wash Wilderness in the lower Hunter Wash Member of the Kirtland Formation in northwestern New Mexic where the new species was found. Ah-shi-sle-pah Wildernessis located in San Juan County, New Mexico, between Chaco Canyon and the De-na-zin Wilderness. Its name is a phonetic transliteration of Navajo “áshįįh łibá” meaning “salt, it is gray.”.
Ahshislesaurus wimani, new species
Etymology: The specific epithet, wimani, honors the first Swedish professor of paleontology, Carl Wiman (1867–1944),from Uppsala University, who worked on fossil vertebrates from the San Juan Basin.
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| Life reconstruction of Ahshislesaurus wimani gen. et sp. nov. based on the holotype (USNM VP-8629) and closely related taxa. Artwork by Sergey Krasovskiy |
Sebastian G Dalman, Steven E. Jasinski, D Edward Malinzak, ... et Anthony R. Fiorillo. 2025. A New saurolophine hadrosaurid (Ornithischia: Hadrosauridae) from the Upper Cretaceous (Campanian) Hunter Wash Member, Kirtland Formation, San Juan Basin, New Mexico. New Mexico Museum of Natural History and Science Bulletin. Fossil Record. 11: 73–114. (September 2025)
