Figure 1.
Locality map, San Juan Basin, New Mexico, southwest USA.
Stratigraphic position of Ziapelta sanjuanensis, gen. et sp. nov., in the De-na-zin Member, Kirtland Formation, and comparison with the stratigraphic positions of other ankylosaurids in New Mexico and Alberta. Alberta stratigraphic column modified from Eberth and Braman [56]. Dates with asterisks represented revised dates from Roberts et al. [16].
Table 1.
Institutional abbreviations.
Figure 2.
Ziapelta sanjuanensis, gen. et sp. nov., (holotype NMMNH P-64484), complete skull.
A, dorsal view; B, ventral view; C, anterior view; D, occipital view; and E, left lateral view. Abbreviations: asca, anterior supraorbital caputegulum; bas, basioccipital; ch, choana; fm, foramen magnum; j, jugal; laca, lacrimal caputegulum; loca, loreal caputegulum; ltf, laterotemporal fenestra; mnca, median nasal caputegulum; nar, external naris; oc, occipital condyle; orb, orbit; pal, palatine; par, parietal; parocc, paroccipital process; pmx, premaxilla; psca, posterior supraorbital caputegulum; pt, pterygoid; q, quadrate; qj, quadratojugal; qjh, quadratojugal horn; snca, supranarial caputegulum; socc, supraoccipital; sqh, squamosal horn; tr, tooth row; v, vomer.
Figure 3.
Ziapelta sanjuanensis, gen. et sp. nov., (holotype NMMNH P-64484), basicranium, in A, left lateral view (anterior is to the left, dorsal is towards the bottom), and B, ventral view (anterior is towards the top). AMNH 5403, Euoplocephalus tutus, basicranium in C, ventral view (anterior is towards the top).
Abbreviations: III, opening for the oculomotor nerve; VII, opening for the facial nerve; V, opening for the trigeminal nerve; IX-X-XI, opening for the glossopharyngeal, vagus, and accessory nerves; XII, opening for the hypoglossal nerve; bas, basisphenoid; bocc, basioccipital; bpt, basipterygoid process; bt, basal tubera; fo, foramen ovale; fos, fossa in basioccipital; oc, occipital condyle.
Figure 4.
Cervical half rings of Ziapelta sanjuanensis.
A) Incomplete first and second cervical half rings of NMMNH P-64484 (holotype), with isolated post-cervical osteoderm, as preserved in situ. First cervical half ring is in posterior view. B) Dorsal view of left medial osteoderm showing smaller interstitial osteoderms, anterior is up. C) Isolated first cervical half ring NMMNH P-66930 (referred specimen) in anterior view. Abbreviations: b, band; g, groove; i, interstitial osteoderm; ld, left distal osteoderm; ll, left lateral osteoderm; lm, left medial osteoderm; mid, midline of the cervical half ring; os, osteoderm; pc os, post-cervical osteoderm; rl, right lateral osteoderm; rm, right medial osteoderm.
Figure 5.
Skull of Ziapelta sanjuanensis compared to those of other North American ankylosaurids.
Interpretive diagrams scaled to approximate same cranial length (from the anterior edge of the premaxilla to the posterior edge of the nuchal crest) for comparative purposes. Abbreviations: asca, anterior supraorbital caputegulum; br, break/plaster; frca, frontal caputegulum; j, jugal; laca, lacrimal caputegulum; loca, loreal caputegulum; mnca, median nasal caputegulum; msca, medial supraorbital caputegulum; mx, maxilla; nas apt, nasal aperture; nasca, nasal caputegulum; nuca, nuchal caputegulum; orb, orbit; pmx, premaxilla; pnca; postnarial caputegulum; poca, postorbital caputegulum; prfca, prefrontal caputegulum; psca, posterior supraorbital caputegulum; qjh, quadratojugal horn; snca, supranarial caputegulum; sqh, squamosal horn.
Figure 6.
Results of the phylogenetic analyses, showing the relationships of Ziapelta sanjuanensis to other ankylosaurids.
Figure 7.
Speculative life restoration of Ziapelta sanjuanensis. Illustration by Sydney Mohr.