Open Paleo

Ahshislepelta

Burns & Sullivan, 2011 Ah-shi-sle-pel-ta

Named after Ah-shi-sle-pah Wash, the locality where the fossil was found, combined with Greek 'pelta' meaning 'shield'; meaning 'Ah-shi-sle-pah Wash shield'

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Ahshislepelta is a monospecific genus of ankylosaur dinosaur from New Mexico that lived during the Late Cretaceous (late Campanian stage, 74.5 Ma) in what is now the Hunter Wash Member of the Kirtland Formation. The type and only species, Ahshislepelta minor, is known only from an incomplete postcranial skeleton of a small subadult or adult individual. It was named in 2011 by Michael Burns and Robert M. Sullivan. Based on the size of the humerus, Ahshislepelta is larger than Pinacosaurus mephistocephalus but smaller than Talarurus and Pinacosaurus grangeri.

Under dispute

The family placement of Ahshislepelta is contested. Arbour and Currie (2015) recover it as one of the most basal ankylosaurids, as do Kuzmin and colleagues (2020), while Rivera-Sylva and colleagues (2018) recover it as the sister of Niobrarasaurus within Nodosauridae and Riguetti and colleagues (2022) place it among nodosaurines. Wiersma and Irmis (2018) and Soto-Acuña and colleagues (2024) find it unstable and prune it.

Diagnosis

  1. Dorsolateral overhang of scapular acromion process reaching 25% of the dorsoventral scapular width, distinctly greater than the 8-21% range seen in other sampled ankylosaurids.
  2. Osteodermal surface texture characterized by uniformly distributed pitted rugosity.
  3. Sparse reticular pattern of neurovascular grooves on osteoderm surface.
  4. Neurovascular foramina extending perpendicularly to obliquely into the osteoderm bone.

Species

Ahshislepelta minor Burns & Sullivan, 2011

Type species

From Latin 'minor' meaning 'smaller', referring to the small adult size of Ahshislepelta relative to other North American ankylosaurids.

Holotype
SMP VP-1930 , State Museum of Pennsylvania
Material
Partial left scapulocoracoid, humerus, and proximal radius; right partial scapulocoracoid; vertebral fragments (cervical and/or dorsal); complete and fragmentary thoracic osteoderms; other unidentifiable postcranial fragments.
Horizon
Hunter Wash Member, Kirtland Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
south side, Ah-shi-sle-pah Wash, New Mexico, United States

References

  1. Burns, M. E.; Sullivan, R. M. (2011). A new ankylosaurid from the Upper Cretaceous Kirtland Formation, San Juan Basin, with comments on the diversity of ankylosaurids in New Mexico. Fossil Record 3 53: 169-178. New Mexico Museum of Natural History and Science.

    Named Ahshislepelta and assigned it to Ankylosaurinae.

    burns2011a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the body length, mass, and hip height estimates, and the appearance features.

    jones2026a
  3. Arbour, V. M.; Currie, P. J. (2015). Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs. Journal of Systematic Palaeontology 14(5): 385-444. Informa UK Limited. doi:10.1080/14772019.2015.1059985

    Recovered Ahshislepelta with Gastonia as the most basal ankylosaurids.

    arbour2015a
  4. Kuzmin, I.; Petrov, I.; Averianov, A. O.; Boitsova, E.; Skutschas, P.; Sues, H. D. (2020). The braincase of Bissektipelta archibaldi — new insights into endocranial osteology, vasculature, and paleoneurobiology of ankylosaurian dinosaurs. Biological Communications 65(2): 85-156. doi:10.21638/spbu03.2020.201

    Recovered Ahshislepelta as the first branch of Ankylosauridae.

    kuzmin2020a
  5. Rivera-Sylva, H. E.; Frey, E.; Stinnesbeck, W.; Carbot-Chanona, G.; Sánchez-Uribe, I. E.; Guzmán-Gutiérrez, J. R. (2018). Paleodiversity of Late Cretaceous Ankylosauria from Mexico and their phylogenetic significance. Swiss Journal of Palaeontology 137(1): 83-93. Pensoft Publishers. doi:10.1007/s13358-018-0153-1

    Recovered Ahshislepelta as the sister of Niobrarasaurus within Nodosauridae.

    rivera-sylva2018a
  6. Riguetti, F.; Pereda-Suberbiola, X.; Ponce, D.; Salgado, L.; Apesteguía, S.; Rozadilla, S.; Arbour, V. (2022). A new small-bodied ankylosaurian dinosaur from the Upper Cretaceous of North Patagonia (Río Negro Province, Argentina). Journal of Systematic Palaeontology 20(1). Informa UK Limited. doi:10.1080/14772019.2022.2137441

    Recovered Ahshislepelta in a nodosaurine polytomy, with very low support.

    riguetti2022b
  7. Wiersma, J. P.; Irmis, R. B. (2018). A new southern Laramidian ankylosaurid, Akainacephalus johnsoni gen. et sp. nov., from the upper Campanian Kaiparowits Formation of southern Utah, USA. PeerJ 6: e5016. PeerJ. doi:10.7717/peerj.5016

    Found Ahshislepelta a wildcard within Ankylosauridae and pruned it.

    wiersma2018a
  8. Soto-Acuña, S.; Vargas, A. O.; Kaluza, J. (2024). A new look at the first dinosaur discovered in Antarctica: reappraisal of Antarctopelta oliveroi (Ankylosauria: Parankylosauria). Advances in Polar Science 35(1): 78-107. doi:10.12429/j.advps.2023.0036

    Found Ahshislepelta a wildcard and pruned it.

    soto-acuña2024a