Kekenodon onamata Beds (McKay 1882

KEKENODON CF. K. ONAMATA Referred specimen: AUGD 2469, partial denticulate tooth crown, from Oruawharo Road, c. 5 km east of Port Albert, North Island, New Zealand, collected by M. Dowson in July 1969. New Zealand Map Series 1 N28:985316, equivalent to 36.2637ºS, 174.46725ºE (NZGD49). Fossil record...

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Bibliographic Details
Main Authors: Corrie, Joshua E, Fordyce, R Ewan
Format: Other/Unknown Material
Language:unknown
Published: 2022
Subjects:
Online Access:https://zenodo.org/record/7386833
https://doi.org/10.5281/zenodo.7386833
Description
Summary:KEKENODON CF. K. ONAMATA Referred specimen: AUGD 2469, partial denticulate tooth crown, from Oruawharo Road, c. 5 km east of Port Albert, North Island, New Zealand, collected by M. Dowson in July 1969. New Zealand Map Series 1 N28:985316, equivalent to 36.2637ºS, 174.46725ºE (NZGD49). Fossil record number Q09/f7902 (original number N28/f0902; New Zealand fossil record file, Geosciences Society of New Zealand). Stratigraphy and age: AUGD 2469 was collected near, and is presumably from, the Mahurangi Limestone, underlying the Miocene Waitemata Group. Matrix from the Mahurangi Limestone consists of whitish grey, fine-grained, sparsely macrofossiliferous and heavily bioturbated rock. Matrix collected from the limestone did not yield the lower Whaingaroan planktonic foraminifera Globigerina (Subbotina) angiporoides Hornibrook, 1965. The presence of Globigerina euapertura Jenkins, 1960 indicates an upper Whaingaroan- Waitakian (c. 28.1 –21.7 Mya; Carter, 1969), contemporaneous with the Kekenodon Beds that produced NMNZ Ma 306. Description Dentition: A single, denticulate tooth crown is preserved (Fig. 10). The apex of the primary denticle is missing and crushing and cracks are prolific on all surfaces of the crown, indicating post-mortem deformation. The crown has a tall, triangular profile that is vertically oriented. A prominent anterior carina is present on the primary denticle, which is markedly larger than all preserved accessory denticles. The lower-half of the anterior surface of the crown is eroded, although the profile of the tooth suggests at least one accessory denticle was present just above the enamelodentin junction.Two large and robust posterior accessory denticles are preserved with possible additional denticles (now lost) located more basally. There is no indication of an ecto- or entocingulum. The enamel on one surface of the crown displays a slight wrinkled ornament, which appears natural, possibly indicating the lingual surface of the crown. In contrast, enamel on the inferred labial surface is ...