High-Latitude Dinosaur Nesting Strategies during the Latest Cretaceous in North-Eastern Russia

• Published in: Diversity
• Main Authors: Amiot, Romain, Golovneva, Lina, B, Godefroit, Pascal, Goedert, Jean, Garcia, Géraldine, Lécuyer, Christophe, Fourel, François, Herman, Alexei, B, Spicer, Robert, A
• Other Authors: Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Komarov Botanical Institute of Russian Academy of Science, Russian Academy of Sciences Moscow (RAS), Royal Belgian Institute of Natural Sciences (RBINS), Centre de Recherche en Paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de paléontologie, évolution, paléoécosystèmes, paléoprimatologie UMR 7262 (Palevoprim Poitiers ), Université de Poitiers = University of Poitiers (UP)-Centre National de la Recherche Scientifique (CNRS), Équipe 3 - Écologie, Évolution, Écosystemes Souterrains (E3S), Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS), Geological Institute of the Russian Academy of Sciences, The Open University Milton Keynes (OU), Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Beijing (CAS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: dinosaur; reproduction; near-polar latitudes; oxygen isotopes; carbon isotopes; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; Chukotka
• Online Access: https://hal.science/hal-04127789; https://hal.science/hal-04127789/document; https://hal.science/hal-04127789/file/84%20Amiot%20et%20al.%20%282023%29%20Diversity.pdf; https://doi.org/10.3390/d15040565

International audience Dinosaur eggshell fragments attributed to the oofamilies Spheroolithidae and Prismatoolithidae and recovered from the latest Cretaceous Kakanaut Formation of North-eastern Russia (Chukotka) constitute one of the northernmost records of dinosaur reproductive behaviors. The high palaeolatitude of the locality (~75° N), as well as the cool near-polar climate, where summer temperatures only averaged 20 °C during the warmest month, dark near-freezing winters and egg incubation that could have lasted several months, raise questions about dinosaur reproductive strategies, particularly in terms of the timing of egg laying. In order to investigate seasonal aspects of Kakanaut dinosaur reproductions, carbonate from eggshell fragments have been analyzed for their oxygen and carbon isotope compositions, along with the oxygen and carbon isotope compositions of apatite phosphate and structural carbonate of associated theropod, hadrosaur and ankylosaur teeth as well as lepisosteid fish scales. Stable oxygen and carbon isotope compositions of eggshells from the Kakanaut Formation together with those of associated adult dinosaur teeth and fish scales reveal differences in mineralization timing between eggshells and teeth and show that eggs were laid at the very beginning of spring when snowmelt drained from nearby highlands. We propose that Kakanaut dinosaurs laid their eggs at the very beginning of spring in order to accommodate an incubation period that lasted several months. This timing would also benefit from mild temperatures and increasing food availability when the eggs hatch, allowing the hatchlings to grow large enough to survive the next winter or perhaps follow adult animals in their migration southwards.