Dinosaur sanctuary on the Chatham Islands, Southwest Pacific: First record of theropods from the K–T boundary Takatika Grit

• Published in: Palaeogeography, palaeoclimatology, palaeoecology palaeoclimatology, palaeoecology, 2006-01, Vol.230 (3), p.243-250
• Main Authors: Stilwell, Jeffrey D., Consoli, Christopher P., Sutherland, Rupert, Salisbury, Steven, Rich, Thomas H., Vickers-Rich, Patricia A., Currie, Philip J., Wilson, Graeme J.
• Format: Article
• Language: English
• Subjects: Chatham Islands; Cretaceous–Tertiary boundary; Dinosaur; Lycopodiopsida; New Zealand; Palaeobiogeography; Theropoda
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/j.palaeo.2005.07.017

Cretaceous–Tertiary (K–T) boundary (ca. 65 Ma) sections on a Southwest Pacific island containing dinosaurs were unknown until March 2003 when theropod bones were recovered from the Takatika Grit on the remote Chatham Islands (latitude 44° S, longitude 176° W), along the Chatham Rise. Tectonic and palaeontologic evidence support the eastward extension of a ca. 900 km land bridge that connected the islands to what is now New Zealand prior to the K–T boundary. The Chathams terrestrial fauna inhabited coastal, temperate environments along a low-lying, narrow, crustal extension of the New Zealand subcontinent, characterised by a tectonically dynamic, volcanic landscape with eroding hills (horsts) adjacent to flood plains and deltas, all sediments accumulating in grabens. This finger-like tract was blanketed with a conifer and clubmoss (Lycopodiopsida) dominated forest. The Chatham Islands region would have, along with New Zealand, provided a dinosaur island sanctuary after separating from the Gondwana margin ca. 80 Ma.