Living on the edge – Diversity patterns of hybodontiform shark-like chondrichthyans prior to the biotic turnover at the Jurassic–Cretaceous transition

Autor(en)

Sebastian Stumpf, Charlie Underwood, Gilles Cuny, Jürgen Kriwet

Abstrakt

The Late Jurassic marks a crucial time interval in the history of life leading to dramatic
episodes of global environmental perturbation at the Jurassic–Cretaceous boundary,
which significantly changed the faunal composition of many vertebrate communities in
both the terrestrial and marine realms. Among marine vertebrates, hybodontiform
shark-like chondrichthyans, which form a supposed sister group to the elasmobranch
crown (i.e., modern sharks, skates and rays), witnessed a diversity decline in marine
ecosystems from the Early Cretaceous onwards before they predominately occurred
in continental environments, where they flourished and adapted to a wide range of
ecological niches until they finally went extinct at the end of the Cretaceous. However,
the controlling factors underlying post-Jurassic hybodontiform diversity dynamics
remain unresolved. Hybodontiforms, whose fossil record is dominated by isolated
teeth, have been reported from various European Late Jurassic localities so far. Our
knowledge of hybodontiforms, however, still is very insufficient so that their diversity,
ecology and distribution prior to the Jurassic–Cretaceous transition remain poorly
understood. Nevertheless, this is of utmost importance for unravelling the response of
these iconic shark-like chondrichthyans to the biotic turnover at the Jurassic–
Cretaceous boundary. We provide a synopsis of the European Late Jurassic fossil
record of hybodontiforms including a historically collected tooth assemblage from the
Kimmeridgian of Poland and well-preserved but largely unstudied skeletal material
from the Kimmeridgian of Normandy, the Kimmeridge Clay Formation of England and
the Solnhofen Archipelago of Germany, and discuss their significance for better
understanding Mesozoic chondrichthyan life prior to the Jurassic–Cretaceous
boundary. Late Jurassic hybodontiform communities are dominated by large-bodied
taxa of higher trophic position, indicating quite uniform distributional patterns
characterized by epipelagic forms that were able to cross deeper marine areas.
Although less well understood, small-bodied hybodontiforms appear to have been
more diverse taxonomically and ecologically and even more widely distributed than
previously thought.

Organisation(en)

Institut für Paläontologie

Band

142

Seiten

89

Anzahl der Seiten

1

Publikationsdatum

09-2021

Peer-reviewed

Ja

ÖFOS 2012

105118 Paläontologie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/8e2f2556-e900-47d1-a83c-1fa9762001f9