New Zealand’s Reptiles

Press, Volume CX, Issue 32352, 18 July 1970, Page 6

New Zealand’s Reptiles

. (Contributed by the Canterbury Museum)

From September, 1969, to April of this year, Dr Samuel P. Welles, of the University of California at Berkeley, studied the fossil bones of reptiles that swam in New Zealand seas some 70 million years ago. The work was supported financially by the United States Educational Foundation in New Zealand, the geology and zoology departments of the University of Canterbury, the New Zealand Geological Survey, and the Canterbury Museum. Dr Welles was provided working and laboratory space by the University geology department Dr Welles left Christchurch on April 28 after completing a first draft of a report on his findings, written in collaboration with the museum’s geologist, and which will be published by the museum. During the 110 years since the first discovery of fossil reptiles tn the Cretaceous rocks of New Zealand, two main sorts have been found. The plesiosaurs had broad flat bodies like shell-less turtles, powerful paddle-like limbs, and short tails without fins. Some plesiosaurs had necks as long as 22ft and have been described as a snake threaded through the body of a turtle. Giant Lizards The mosasaurs were giant marine monitor lizards, with long finned tails, paddle-like limbs, and long jaws armed with many teeth. Under Dr Welles’s direction two fossil reptiles that swam in these ancient seas

have been collected. The first is a new species of mosasaur of which the first remains (two vertebrae) were found at the Waipara River in 1963. The other reptile is a plesiosaur found at the Conway River by Mr Guyon Warren of the New Zealand Geological Survey. The plesiosaur bones are embedded in hard limestone concretions and are not yet fully removed from the rock. In some specimens the hard rock has been removed from the bones by the use of a small percussion drill operated by compressed air. The tungsten carbide bit vibrates backward and forward at very high speed rapidly chipping away the rock, and at the same time emitting a penetrating highpitched whine. In other specimens, -chemical preparation has been used rather than mechanical. The specimen is placed in a bath (plastic baby-baths have been used) filled with dilute acetic acid. The limecemented rock disintegrates in the acid, leaving the bones a little weakened, but freed from the rock and available for study. This method has produced the most perfect bones as full of detail as those of modern animals. On Display The specimens collected by Dr Welles are at the Canterbury Museum where they will form important additions to our research collection of New Zealand fossil reptiles as well as spectacular display specimens. Casts of selected specimens, as well as some individual bones, will be handed to the University of Canterbury for teaching and display. The first and the last major work on New Zealand fossil reptiles was published by

James Hector in 1874. He showed that in the Cre taceous seas of New Zealand there lived both short and long-necked plesiosaurs and this has been confirmed by Dr Welles. Many of the specimens on which Hector based his species are now regarded as indeterminable, but one of his long-necked plesiosaurs, happily named Mauisaurus Haasti, and based on specimens collected by Julius Haast at the Jed River, Cheviot, in 1870 is still regarded as valid. Of the mosasaurs, Hector’s two species Tylosaurus haumuriensis and Taniwhasaurus oweni, both based on specimens from Haumuri Bluff, are confirmed as valid species. We also have the new species from the Waipara River which is to be placed in the genus Prognathodon, and a new species of Mosasaurus from Cheviot based on fossil bones from the museum’s collection.—D.R.G.