A molecular characterization of a newly discovered megafaunal fossil site in North Canterbury, South Island, New Zealand

Abstract

In January 2008 an assemblage of large fossil bones was unearthed in a field near Waikari, North Canterbury, South Island, New Zealand. We describe this new fossil site, Rosslea, and provide an inventory of the excavated material. The bones were generally well preserved although stained deep brown, typical of peat preservation. Eight Rosslea bones were 14C AMS dated and median calibrated ages ranged from 7839 to 1482 years BP. Ancient DNA was isolated from 14 bones and a single piece of eggshell. Genetic species identifications based on mitochondrial DNA matched those based on morphology, confirming that three species of extinct moa (Aves: Dinornithiformes) were present. Also, remains of an extinct South Island Adzebill (Aptornis defossor) were identified. The species composition in the Rosslea assemblage proved typical for the time and region but comparative analyses revealed that each of five major fossil deposits in the area displayed a significantly different relative abundance of moa taxa, despite their proximity and relative contemporaneity (all contain Holocene moa bones). Lastly, indications of DNA damage and failed attempts to amplify nuclear DNA indicated that DNA preservation at Rosslea was relatively poor compared to the preservation known from adjacent deposits