Neogene echinoids from the Cayman Islands, West Indies: regional implications

Donovan, S.K.; Jones, B.; Harper, D.A.T.

Abstract

The first fossil echinoids are recorded from the Cayman Islands. A regular echinoid, Arbacia? sp., the spatangoids Brissus sp. cf. B. oblongus Wright and Schizaster sp. cf. S. americanus (Clark), and the clypeasteroid Clypeaster sp. are from the Middle Miocene Cayman Formation. Test fragments of the mellitid clypeasteroid, Leodia sexiesperforata (Leske), are from the Late Pleistocene Ironshore Formation. Miocene echinoids are preserved as (mainly internal) moulds; hence, all species are left in open nomenclature because of uncertainties regarding test architecture. All Miocene taxa are recorded from single specimens apart from the 27 assigned to Brissus. Schizaster sp. cf. S. americanus (Clark) is compared to a species from the Oligocene of the south-east USA. Brissus sp. cf. B. oblongus is close in gross morphology to a taxon from the Miocene of Malta. Leodia sexiesperforata is identified from fragments with confidence, being the only extant Antillean sand dollar with elongate ambulacral petals that is limited to carbonate substrates. The Miocene echinoids of Grand Cayman, although of limited diversity, are mainly comprised of genera common in comparable mid-Cenozoic carbonate environments.

Citation

Donovan, S., Jones, B., & Harper, D. (2016). Neogene echinoids from the Cayman Islands, West Indies: regional implications. Geological Journal, 51(6), 864-879. https://doi.org/10.1002/gj.2703

• Journal Article Type: Article
• Acceptance Date: Jun 8, 2015
• Online Publication Date: Sep 2, 2015
• Publication Date: 2016-11
• Deposit Date: Sep 4, 2015
• Journal: Geological Journal
• Print ISSN: 0072-1050
• Electronic ISSN: 1099-1034
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 51
• Issue: 6
• Pages: 864-879
• DOI: https://doi.org/10.1002/gj.2703
• Public URL: https://durham-repository.worktribe.com/output/1423390