Eucynodont teeth from the Late Triassic of Krasiejów, Southern Poland

ABSTRACT

Recent discoveries of Mammaliamorph teeth in the Keuper of southern Poland have extended the global record of eucynodonts in the Late Triassic and revealed a significant diversity of the group at that time. Here, we expand on this record with the description of new cynodont postcanine teeth from the Krasiejów bone bed. They show the dental morphology typical for Dromatheriidae, with a single root and crown without cingulum. We assigned them to Polonodon woznikensis, described from Woźniki. None of the 38 teeth from Krasiejów and Woźniki exhibit signs of serious wear, potentially indicating a very fast rate of tooth replacement in Polonodon.

KEYWORDS:

• Synapsids
• mammals origin
• Late Triassic
• sclerobiont
• heterochrony

Acknowledgments

We thank Dawid Dróżdż for work on 3D models of teeth, preparing Figure 2, and discussion on text. We are thankful to Jerzy Dzik for discussion and final editing of the text. We thank Fernando Abdala for comment to the manuscript. We thank all students, amateurs, and professionals who participated in the excavations in the clay-pit at Krasiejów. We are also grateful to the following staff members of the Institute of Paleobiology, Polish Academy of Sciences in Warsaw: Dr. Cyprian Kulicki for SEM micrographs and Mr. Marian Dziewiński for help during fieldworks. For the specimens UOPB-1177-1179 (Figure 2) X-ray microtomography with scanner Zeiss XRadia MicroXCT-200 housed in the Institute of Paleobiology PAS was conducted by Katarzyna Janiszewska and financed by NanoFun POIG.02.02.00-00-025/09

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Narodowe Centrum Nauki as the project No. 2017/27/B/NZ8/01543 (grant of Tomasz Sulej).