Open Paleo

Gastonia

Kirkland, 1998 gas-TOH-nee-a

Named for American fossil collector Robert Gaston, who discovered the specimens.

137.1–132.6 million years ago Valanginian, Early Cretaceous
Early Cretaceous stages

Gastonia is a genus of herbivorous ankylosaurian dinosaur from the Early Cretaceous of North America, around 139 to 125.77 million years ago. It is often considered a nodosaurid closely related to Polacanthus. Gastonia has a sacral shield and large shoulder spikes.

Diagnosis

  1. Three sacral vertebrae (vs. four in Polacanthus); ilia with slender, anteriorly diverging preacetabular processes (vs. short and nearly parallel in Polacanthus).
  2. Anterior trochanter fused to greater trochanter forming a ridge, unlike free anterior trochanter in Hoplitosaurus.
  3. Tibia considerably shorter and more robust than in Polacanthus and Hylaeosaurus, with strongly flaring proximal and distal ends.
  4. Dorsal armor uniquely characterized by scutes bordered by radially directed ridges around their margins.
  5. Skull unique among all known ankylosaurs in having a broad premaxillary notch, posteriorly placed narial openings, and basisphenoid with elongate basipterygoid processes forming a gliding joint with the unfused pterygoids.

Species (2)

Gastonia burgei Kirkland, 1998

Type species

Named for Donald L. Burge, director of the College of Eastern Utah Prehistoric Museum.

Holotype
CEUM 1307 , College of Eastern Utah Prehistoric Museum
Material
Skull; from limestone layer in bonebed with disarticulated cranial and postcranial elements of minimum four polacanthids, an iguanodontid, and the type of Utahraptor ostrommaysorum.
Horizon
upper Yellow Cat Member, Cedar Mountain Formation, Valanginian, Early Cretaceous , 137.1–132.6 million years ago
Locality
Yellow Cat Quarry, Utah, United States

Gastonia lorriemcwhinneyae Kinneer et al., 2016

Honors Lorrie McWhinney, who discovered the Gastonia bone bed (Lorrie's Site) in 1999.

Holotype
DMNH 49877 , Denver Museum of Nature and Science
Material
Skull roof, 23.8 cm wide across the postorbital horn cores and 23.5 cm long anteroposteriorly.
Horizon
lower Ruby Ranch Member, Cedar Mountain Formation, Aptian, Early Cretaceous , 121.4–113.2 million years ago
Locality
Lorrie's Site, Utah, United States Kinneer and colleagues (2016) catalog the site as DMNH locality 2183 and place its bone bed in the lower Ruby Ranch Member, noting that Doelling and Kuehne had instead correlated it with the upper Poison Strip Member.
Diagnosis
  1. Flat skull roof, not domed (domed in G. burgei)
  2. Short paroccipital processes, proportionally less expanded distally
  3. Scapular blade parallel-sided, only slightly expanded distally in adults
  4. Postacetabular process of ilium only 36% the length of the preacetabular process (56% in G. burgei)
  5. Ischium smoothly curved ventromedially, lacking the midshaft kink present in G. burgei
  6. Basisphenoid less expanded distally and proportionally shorter relative to basicranial length (more expanded and longer in G. burgei)

References

  1. Kirkland, J. I. (1998). A polacanthine ankylosaur (Ornithischia: Dinosauria) from the Early Cretaceous (Barremian) of eastern Utah. Lower and Middle Cretaceous Terrestrial Ecosystems (Lucas, S. G.; Kirkland, J. I.; Estep, J. W., eds.) 14: 271-281. kirkland1998b
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

    paul2024a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a
  4. Kinneer, B.; Carpenter, K.; Shaw, A. (2016). Redescription of Gastonia burgei (Dinosauria: Ankylosauria, Polacanthidae), and description of a new species. Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 282(1): 37-80. Schweizerbart. doi:10.1127/njgpa/2016/0605 kinneer2016a