60 A massive tree-like coral from Oamaru
Scleractinia, Oculinidae: Oculina oamarutica
One of the more unusual coral holotypes in the Geology Museum collection is a massive specimen collected from a ‘bed of calcareous tuff’ in an old quarry near Awamoa Creek, south of Oamaru. The base of the largest piece of the coral is about 40 mm in diameter with thick tree-like branches covered with small, widely spaced corallites. Oculina is a type of colonial coral which is found in northern New Zealand in deep water today. However, the fossil specimens from around Oamaru were living in quite shallow water environments.
It was briefly described by Professor James Park, better known for his textbooks on the Geology of New Zealand, in a two-page note published in the Transactions of the New Zealand Institute in 1917.
James Park was an all-round geologist and explorer. Many of his papers were on mining-related topics such as coal and coalfields, igneous rocks and gold deposits from all over New Zealand. His first publication appeared in 1881 and the final one in 1937 – a span of 56 years. However, some of his major contributions to New Zealand geology were the series of NZ Geological Survey Bulletins such as Geology of the Alexandra Sheet (1906), Geology of Cromwell (1908), Queenstown Subdivision (1909) and Geology and Mineral Resources of Western Southland ((1921). It was probably during the course of his work on the Geology of the Oamaru Subdivision (1918) that he collected this interesting new fossil coral.
In a more detailed description of the specimen, Squires (1958) noted that the corallum was very large, with branches up to 40 mm in diameter, while the corallites were up to 4 mm in diameter and arranged spirally on the branches.
Various specimens of the stony coral Oculina oamaruensis. A. OU 206 is the holotype from Awamoa Creek, near Oamaru. B. OU 5129 is a specimen of Bortonian age from Maerewhenua. C-D. OU 212a. E. OU 212b. Two fossil corals of Waitakian age from Kyeburn with the cup-shaped corallites facing outwards. F. OU 212c. A mould from a channel through a large coral; note that the cup-shaped corallites are facing inwards.
— Written by Daphne E Lee and Jeffrey H Robinson
| Specimen number: OU 206 (holotype) | Age: Approximately 35 million years old (late Eocene Runangan) |
| Locality: Small quarry, near Awamoa Creek, south of Oamaru | Rock Formation: Waiareka-Deborah Volcanic Formation |
| Collected by: James Park, c. 1916 | |
| Citation: Park J 1917. On a new species of coral from the lower Oamaruian tuffs near Deborah, Oamaru. Transactions of the New Zealand Institute., 49:396, pl. 27. |
