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Neoichnology and implications for stratigraphy of reworked Upper
Oligocene oysters, Antigua, West Indies

Donovan, S.K.; Harper, D.A.T.; Portell, R.W.; Renema, W.


S.K. Donovan

R.W. Portell

W. Renema


The Late Oligocene oyster Hyotissa antiguensis (Brown) is locally common in the Antigua Formation of Hughes Point, eastern Antigua, Lesser Antilles; it was not commonly bored at that time. Its valves and shells are robust, and reworked into the shallow water near-shore environment in Antigua; it could potentially be incorporated into younger rocks. Its neoichnology includes clues that would facilitate identification of these oysters as reworked fossils. The suite of modern borings found in these specimens includes common Caulostrepsis taeniola Clarke, Gastrochaenolites isp. cf. G. turbinatus Kelly and Bromley and Entobia isp., and rare Oichnus simplex Bromley and Rogerella? isp. The latter three taxa are limited to oyster shell substrates. Of the common ichnotaxa, Caulostrepsis and Gastrochaenolites are particularly prominent in limestone clasts and limestone cemented to oyster shells, which would be an indicator of reworking if found in a post-Oligocene lithified deposit. Caulostrepsis and Gastrochaenolites are relatively less common in oyster shells and valves, and in many specimens are seen to terminate against the shell. Entobia is the only common boring limited to the shell substrate. The fidelity of preservation of modern borings is also superior in limestone clasts. This suite of borings is comparable with those found in the Neogene of the Antillean region.


Oligocene oysters, Antigua, West Indies. Proceedings of the Geologists' Association, 125(1), 99-106.

Journal Article Type Article
Acceptance Date Oct 11, 2013
Online Publication Date Nov 6, 2013
Publication Date 2014-01
Deposit Date Nov 11, 2013
Journal Proceedings of the Geologists' Association
Print ISSN 0016-7878
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 125
Issue 1
Pages 99-106
Keywords Bioerosion, Caulostrepsis, Entobia, Gastrochaenolites, Oichnus, Rogerella.