Success and demise of pycnodont fishes (Neopterygii, †Pycnodontiformes)

Autor(en)

Jürgen Kriwet, Giuseppe Marrama, Giorgio Carnevale, John Joseph Cawley

Abstrakt

The rise of neopterygian fishes in the Late Triassic was associated with the emergence of modifications to the skull that enabled fishes to crush heavily armoured prey items such as crustaceans, echinoderms and molluscs. Three lineages of durophagous fishes were prevalent throughout the Mesozoic: Gingly-modi, †Dapediiformes and †Pycnodontiformes. Of these, pycnodontiforms were taxonomically much more diverse and seemingly very successful during most of the Mesozoic with a fossil record spanning 175 million years. While dapediiforms vanished during the middle Jurassic, pycnodontiforms prevailed but finally went extinct in the middle-late Eocene. The only group still present are the ginglymodians although very reduced in taxonomic diversity and restricted to freshwaters today. Nevertheless, all three groups occupied the same marine ecosystems during the Mesozoic but the role that competitive exclusion and niche partitioning played in their ability to survive alongside each other and the success of one group relative to the others remain unknown. We established diversity patterns and performed geometric morphometric analyses using the lower jaw as constraint for feeding adaptations and the body shape as constraint for habitat occupation to better understand competition and its consequences but also why pycnodonts seemingly were more successful but still died out. According to our results, pycnodonts were more successful than the others in terms of taxonomic diversity. Moreover, compe-tition between dapediiforms and ginglymodians occurred, while pycnodontiforms were performing a different role in the ecosystem. Competition reduction between pycnodontiforms and the other two durophagous clades resulted in niche partitioning. While dapediiforms were outcompeted, ginglymo-dians evaded competition with pycnodontiforms by adapting exclusively to freshwater habitats in the Late Cretaceous. Competition within pycnodontiforms was reduced by developing different feeding strategies. Extinction of pycnodontiforms in the Palaeogene probably did not result from competition with emerging modern coral fishes, but other reasons might have been more important.

Organisation(en)

Institut für Paläontologie

Externe Organisation(en)

Università degli Studi di Torino

Seiten

85-85

Anzahl der Seiten

1

Publikationsdatum

2019

Peer-reviewed

Ja

ÖFOS 2012

105118 Paläontologie, 106003 Biodiversitätsforschung

Sustainable Development Goals

SDG 14 – Leben unter Wasser, SDG 15 – Leben an Land

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/86ee07c8-c307-4a2f-9bcf-53732da87607