Journal Article/Dataset

PUBDB-2026-01244

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Data from: United by chewing: Hunter-Schreger band-like pattern and wavy enamel in a fossil crocodile suggest functional convergence with mammals and dinosaurs

Price, S. W. T. ; Prondvai, E. ; Horváth, K. ; Gutowski, O.DESY* ; Beale, A. ; DESY, D. E. (Sponsor)

2025
The Royal Society London

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Please use a persistent id in citations: doi:10.1098/rspb.2025.1992  doi:10.5061/DRYAD.6Q573N6C9

Abstract: Tooth enamel of most mammals shows alternating light-dark bands, called Hunter-Schreger bands (HSB), in longitudinal sections caused by a decussating arrangement of bundles of prisms, the unit building blocks of mammalian enamel. HSB is thought to increase resistance to abrasive food and mitigate crack propagation and hence is considered a mammalian adaptation to high-efficiency mastication. Here we report for the first time the presence of HSB-like features in the tooth enamel of a non-mammalian amniote, Iharkutosuchus, an extinct herbivorous crocodile with strong heterodonty and a unique chewing mechanism. Lacking mammal-like decussating prisms as revealed by traditional visualization techniques, the enigmatic nature of this HSB-like enamel pattern in Iharkutosuchus was only explainable using X-ray diffraction computed tomography which showed its purely crystallographic origin. Wavy enamel, a well-known structure in herbivorous ornithopod dinosaurs with shearing-type mastication, is also demonstrated in Iharkutosuchus. The unexpected finding of both enamel features in this herbivorous crocodile speaks for their role in high-efficiency chewing. However, the profoundly different structural background of mammalian and crocodilian HSB demonstrated here and the phylogenetic distribution of both HSB and wavy enamel imply nanostructure-scale convergences highlighting the importance of mastication-related challenges in driving dentary evolution of amniotes.

Keyword(s): Hunter-Schreger bands ; crocodilian tooth enamel ; Iharkutosuchus ; wavy enamel ; XRD-CT ; chewing-related adaptation ; Convergent evolution ; FOS: Biological sciences

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Contributing Institute(s):

1. PETRA-D (FS-PETRA-D)

Research Program(s):

1. 633 - Life Sciences – Building Blocks of Life: Structure and Function (POF4-633) (POF4-633)
2. 6G3 - PETRA III (DESY) (POF4-6G3) (POF4-6G3)

Experiment(s):

1. PETRA Beamline P07 (PETRA III)

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Database coverage:
; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; National-Konsortium ; PubMed Central ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection ; Zoological Record

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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Journal Article Prondvai, E. (Corresponding author) ; Horváth, K. ; Price, S. (Corresponding author)Extern* ; Gutowski, O.DESY* ; Beale, A. M.Extern*
United by chewing: Hunter-Schreger band-like pattern and wavy enamel in a fossil crocodile suggest functional convergence with mammals and dinosaurs
Proceedings of the Royal Society of London / Series B 293(2064), 20251992 (2026) [10.1098/rspb.2025.1992]2026     Files BibTeX | EndNote: XML, Text | RIS

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