Image: Ankylosaurus cervical half rings

Description: Portions of Ankylosaurus (AMNH 5895) cervical half rings compared with the first cervical half ring of Euoplocephalus (AMNH 5406), and Ankylosaurus (AMNH 5895) postcervical osteoderms. (A) Complete (but distorted) first cervical half ring of Euoplocephalus (AMNH 5406) in ?anterior view, showing arrangement of osteoderms on the underlying band of bone, and (B) interpretive illustration. The medial and lateral osteoderm pairs sit atop flat band segments, but the distal osteoderms slightly envelop the tip of their band segments. (C) Portion of Ankylosaurus first cervical half ring with lateral and distal osteoderms in external view, and (D) interpretive illustration. (E) Portion of same half ring in internal view, and (F) interpretive illustration. Carpenter (2004) suggested that a second fragment of cervical half ring bearing a single osteoderm was a continuation of the segment figured here in C–F. In G–J, the cervical half ring fragment illustrated in C–F is located to the left, and the second fragment is located on the right. (G) These pieces (here in oblique anterior or posterior internal view) cannot be reunited along their broken edges and probably do not represent the same half ring; (H) interpretive illustration. (I) The osteoderm morphology of the fragment of cervical half ring with only a single preserved osteoderm (here in oblique anterior or posterior external view) is similar to that of the distal osteoderm of the more complete specimen, but is substantially larger, and thus probably represents a distal osteoderm from the second cervical half ring, which is typically larger in specimens of Euoplocephalus (Arbour and Currie 2013a); (J) interpretive illustration. (K) and (L) large postcervical osteoderms from Ankylosaurus (AMNH 5895), probably derived from medial positions along the back; the osteoderm in (L) is similar in shape to those immediately posterior to the medial cervical half ring osteoderms in Saichania (MPC 100/151) (Arbour and Currie 2013a, 2013b). b, cervical half ring band; dos-1, distal osteoderm of the first cervical half ring; dos-2, distal osteoderm of the second cervical half ring; los-1, lateral osteoderm of the first cervical half ring; mos-1, medial osteoderm of the first cervical half ring; p, plaster.
Title: Ankylosaurus cervical half rings
Credit: http://www.facetsjournal.com/doi/10.1139/facets-2017-0063
Author: Victoria M. Arbour, Jordan C. Mallon
Usage Terms: Creative Commons Attribution 4.0
License: CC BY 4.0
License Link: https://creativecommons.org/licenses/by/4.0
Attribution Required?: Yes