Reef Fish Beware! Aggressive Mimicry in a Pycnodontid?

Kölbl-Ebert M, Ebert M, Bellwood DR, Schulbert C (2019)

Publication Language: English

Publication Type: Conference contribution, Abstract of a poster

Publication year: 2019

City/Town: München

Pages Range: 82

Conference Proceedings Title: Abstracts of the 90th Annual Meeting of the Paläontologische Gesellschaft

Event location: München DE

ISBN: ISBN 978-3-946705-07-9


Pycnodontiformes are an extinct order of Actinopterygian fishes, present from the Late Triassic
(Norian) to the Eocene. Their mostly deep, laterally compressed bodies and comparatively large fins
indicate that these fishes were mostly highly manoeuvrable reef fish. With their characteristic durophagous
dentition, columnar to incisiform anterior teeth (on premaxilla and dentary) and the posterior
crushing teeth of the prearticular and vomer, the whole group was highly specialized as predators on
hard-shelled organisms.
In 2016, however, a new pycnodontid was found in the quarry of Ettling (Markt Pförring, Bavaria;
Late Jurassic) by the excavation team of the Jura-Museum Eichstätt. The most striking feature of this
new pycnodontid, Piranhamesodon pinnatomus Kölbl-Ebert et al., 2018 (JME-ETT4103), is its unusual
dentition: It has long, pointed teeth at the front (on premaxilla and dentary), dagger-shaped teeth
with a sharp, posterior cutting edge along the exterior-most tooth row of the vomer, and triangular
teeth with serrations on their anterior margin along the exterior-most tooth row of the prearticulars.
As revealed by CT-scanning, the inner teeth of prearticular and vomer are limpet-shaped cones on a
columnar tooth base.
The “fangs” along the exterior-most tooth row of the prearticulars and vomer of Piranhamesodon
pinnatomus interact like scissors; a comparison of their functional morphology with other actinopterygians
stress the exceptional high bite-force (a legacy of their pycnodont ancestry), which is comparable
to modern piranhas, suggesting a completely unusual mode of predation compared to all other known
We propose this species to have exploited aggressive mimicry: Seemingly harmless and inconspicuous
through the typical pycnodontid shape and possibly aided by corresponding colouring, it may have
approached and then attacked unsuspecting other fish in the reef, biting and tearing a mouthful of flesh
or fin from their unwary prey. Alternatively, it may also have acted at least occasionally as scavenger.

Authors with CRIS profile

Involved external institutions

How to cite


Kölbl-Ebert, M., Ebert, M., Bellwood, D.R., & Schulbert, C. (2019, September). Reef Fish Beware! Aggressive Mimicry in a Pycnodontid? Poster presentation at Annual Meeting of the Paläontologische Gesellschaft, München, DE.


Kölbl-Ebert, Martina, et al. "Reef Fish Beware! Aggressive Mimicry in a Pycnodontid?" Presented at Annual Meeting of the Paläontologische Gesellschaft, München Ed. Paläontologische Gesellschaft, München, 2019.

BibTeX: Download