Invictarx
From Latin 'invictus' meaning 'invincible' or 'unconquerable' and 'arx' meaning 'fortress', in reference to the well-armored nature of ankylosaurs. The species name is from Greek 'Zephyrus' meaning 'western wind'.
Invictarx is a monospecific genus of nodosaurid dinosaur from New Mexico that lived during the Late Cretaceous (lower Campanian, 78.5 Ma) in what is now the upper Allison Member of the Menefee Formation. The type and only species, Invictarx zephyri, is known from three isolated, incomplete postcranial skeletons. It was named in 2018 by Andrew T. McDonald and Douglas G. Wolfe. Invictarx shares similarities with Glyptodontopelta from the Naashoibito member of the Ojo Alamo Formation, New Mexico.
Diagnosis
- Cervical/pectoral and thoracic osteoderms with smooth surface texture, abundant randomly distributed pits, minimal neurovascular grooves
- Some thoracic osteoderms with low rounded keel bearing deep craniocaudal groove along apex
- Probable co-ossified pelvic shield of polygonal osteoderms of uniform size
Species
Invictarx zephyri McDonald & Wolfe, 2018
Type species
From the genitive form of Greek 'Zephyrus', the god of the western wind, referring to the blustery conditions that prevail among the outcrops where the specimens were discovered.
- Holotype
- WSC 16505 , Western Science Center
- Material
- Incomplete postcranial skeleton with dorsal rib fragments and six identifiable osteoderms
- Horizon
- Juans Lake Bed, Allison Member, Menefee Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
- Locality
- New Mexico, United States
References
- McDonald, A. T.; Wolfe, D. G. (2018). A new nodosaurid ankylosaur (Dinosauria: Thyreophora) from the Upper Cretaceous Menefee Formation of New Mexico. PeerJ 6. PeerJ. doi:10.7717/peerj.5435 mcdonald2018a
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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