Drill holes in Australian Cainozoic brachiopods

Abstract

The fossil record of drill holes in marine invertebrates has received a considerable amount of interest from paleontologists, primarily due to its importance for reconstructing the history of interactions between drilling predators and their prey. Such drill holes have been described in numerous studies of Paleozoic brachiopods but rarely in those focusing on brachiopods of the post-Paleozoic, a striking pattern given that in the late Mesozoic and Cainozoic drilling gastropods diversified and frequencies of drilled molluscs increased dramatically. During the past several years, however, drilled brachiopods were reported in several studies of the Mesozoic and Cainozoic, suggesting that this phenomenon may be more common than has been previously assumed. Here we report on 10 genera of brachiopods from four Cainozoic basins in Australia of which 7 shows evidence of having been drilled by predators. Of 298 specimens examined, 38 contain a single complete hole. Drilled specimens were identified in all 4 basins and in all stratigraphic units. When considered in the context of recent reports of drilled Cainozoic brachiopods, these Australian brachiopods further imply that drilling predation on these invertebrates was geographically, taxonomically and temporally widespread.

The post‐Palaeozoic fossil record of drilling predation on lingulide brachiopods

“…1). The latter is a semi-quantitative approach employed for assessing selectivity in drilling location by predators (Złotnik 2001;Baumiller et al 2006;Tuura et al 2008), which can be used when quantitative strategies based, for example, on landmark approaches (e.g. Roopnarine & Beussink 1999;Hoffmeister et al 2004) are impractical.…”

“…; Tuura et al . ), which can be used when quantitative strategies based, for example, on landmark approaches (e.g. Roopnarine & Beussink ; Hoffmeister et al .…”

Uncovering the holes and cracks: from anecdote to testable hypotheses in predation studies

“…; Tuura et al . ; Hiller ). It remains unclear whether predation has been important in the post‐Palaeozoic restriction of brachiopods as suggested by Stanley (), but it remains a plausible factor (Jablonski ) and a matter which may be resolved with a greater body of data.…”

“…; Visaggi & Kelley ) and Australasia (Tuura et al . ; Hiller ). Further expansion of these studies will provide an understanding of broader scale spatial variation in predation pressure over evolutionary time.…”

Late Eocene (Priabonian) brachiopod fauna from Dnipropetrovsk, eastern Ukraine

“…However, in the Cenozoic drilling predation on brachiopods was only occasionally intense (e.g. Baumiller & Bitner 2004;Harper 2005Harper , 2011Baumiller et al 2006;Tuura et al 2008), usually traces of drill holes are infrequent, often in barely 1% of specimens (Taddei Ruggiero & , Bitner et al 2013a, Bitner & Müller 2015, Bitner & Motchurova-Dekova 2016. At Dnipropetrovsk the frequency of drill holes in brachiopods is relatively high; 130 drilled specimens (9.6%) were found among 1356 specimens examined (Fig.…”