Early Cretaceous vertebrate and invertebrate fossils from Dariyan Formation, southern Iran

ABSTRACT

The Mesozoic fauna of southwestern Asia remains poorly understood. Here, we report on an assemblage of marine invertebrates and vertebrates from the Lower Cretaceous Dariyan Formation of Iran. The Dariyan Formation consists of 60 m of carbonates deposited in shallow seas. These deposits exhibit a high abundance of foraminifera that belong to nine genera and 14 species. Based on the succession of microfossil assemblages (Choffatella decipiens Range Zone, Radiolaria flood Range Zone, Globiogerinelloides blowi Range Zone, Mesorbitolina parva Range Zone), we propose that the Sivand fossiliferous deposits are Early Aptian (Bedoulian) through early Late Aptian (Early Gargasian) in age. Fossil vertebrates are preserved in the lower part of the formation. A diverse assemblage of fishes is present, including Aspidorhynchiformes, Ichthyodectiformes, Pycnodontiformes, Aulopiformes, and Clupeomorpha, and one genus of chelonioid turtle that is either a member of the Protostegidae or Dermochelyidae. The similarities in the fish assemblages of the Dariyan Formation of Iran with the Santana Formation of Brazil and the Tlayúa Quarry in south-central Mexico show that these fishes were distributed throughout the equatorial region and were widely spread in the shallow seaways of the Early Cretaceous.

KEYWORDS:

• Cretaceous
• biostratigraphy
• foraminifera
• fish
• turtle
• Iran

Acknowledgments

This project has been sponsored by the Center for International Scientific Studies and Collaboration (CISSC), Ministry of Science, Research and Technology, Iran awarded to A. Bahrami in 2019, and by the Slovak Research and Development Agency under the contract No. APVV-18-0251 awarded to M. Kundrát in 2019.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Center for International Scientific Studies and Collaboration (CISSC), Ministry of Science, Research and Technology, Iran awarded to A. Bahrami in 2019, and by the Slovak Research and Development Agency under the contract No. APVV-18-0251 awarded to M. Kundrát in 2019.