Abstract
Cenozoic faunal exchanges between Europe, Asia, Africa and America played a key role in shaping modern-day Eurasian ecosystems with dispersal pathways controlled by the dynamics of natural palaeogeographic barriers (e.g., deserts, isthmuses, large water bodies, etc.). The South Caucasus is a mountainous region between Asia and Europe, which served as an important dispersal route during the late Cenozoic for the intercontinental exchanges of diverse terrestrial vertebrates. The Pliocene geology of this region is dominated by volcanic and volcaniclastic deposits that are generally not favourable for fossil preservation. However, a few rich fossil vertebrate faunas do occur although they lack comprehensive palaeoenvironmental and age constraints. In this paper, we present an integrated study of the stratigraphy and palaeontology of the Jradzor section located in the Gegham volcanic province of Armenia, to improve knowledge of late Cenozoic dispersal pathways. The 57-m-thick succession comprises 19 fossiliferous horizons with at least 48 identified vertebrate taxa (excluding birds). The palaeoenvironmental reconstruction suggests that the succession was deposited within a short-lived dammed lake that was subject to pyroclastic density flows, and later evolved into soil catenas. Taphonomic observations indicate that pyroclastic flows caused a high mortality of small-size vertebrates in most fossiliferous horizons, while a catastrophic lahar buried the large vertebrate fauna. Multiproxy dating places the studied section between 4.3 and ∼ 3.03 Ma and the mammalian fauna correlates to the MN15. Comparison with similar age localities from across the region shows that Jradzor comprises the most continuous Pliocene succession with the highest number of fossil taxa and fills the MN15 interregional gap. The rich fossil vertebrate faunas have Asian and primarily European affinities. Findings show that the South Caucasus was a significant dispersal route for terrestrial vertebrates between Europe, Asia and Africa, and is of crucial importance for understanding Eurasian palaeogeography.
| Original language | English |
|---|---|
| Article number | 111685 |
| Pages (from-to) | 1-27 |
| Number of pages | 27 |
| Journal | Palaeogeography, Palaeoclimatology, Palaeoecology |
| Volume | 625 |
| Early online date | 14 Jun 2023 |
| DOIs | |
| Publication status | Published - 1 Sept 2023 |
Bibliographical note
Funding Information:We would like to thank all participants in excavations at the Jradzor site since 2007. We also thank the JURASSICA Museum for financial support in the organisation of the International Palaeontological Field School in 2019 for the collection of fossils in the field. Special thanks due to: I. Gabrielyan (Yerevan) and S. Pipoyan (Yerevan) for assistance and encouragement during the earliest stages of the study of the site; to Iuliana Vasiliev for help with palaeomagnetic sampling in the field; to Wout Krijgsman (Utrecht) for improvements of the paper structure; to Gerald Mayr (Frankfurt am Main) for preliminary identification; to preparator of the JURASSICA Museum Renaud Roch for preparation of fossils both in the field and in the lab. We would also like to thank the staff of the diatomite mine for their hospitality, administrative and logistic support during all fieldworks. This manuscript would be sloppy and less structured without the help of the editor Falcon Lang (London) and three reviewers: Fabrizio Marra (Rome), Lars van den Hoek Ostende (Leiden) and anonymous reviewer. We are thankful to them for their great corrections and the time taken for the review.
Publisher Copyright:
© 2023 The Authors
Funding
We would like to thank all participants in excavations at the Jradzor site since 2007. We also thank the JURASSICA Museum for financial support in the organisation of the International Palaeontological Field School in 2019 for the collection of fossils in the field. Special thanks due to: I. Gabrielyan (Yerevan) and S. Pipoyan (Yerevan) for assistance and encouragement during the earliest stages of the study of the site; to Iuliana Vasiliev for help with palaeomagnetic sampling in the field; to Wout Krijgsman (Utrecht) for improvements of the paper structure; to Gerald Mayr (Frankfurt am Main) for preliminary identification; to preparator of the JURASSICA Museum Renaud Roch for preparation of fossils both in the field and in the lab. We would also like to thank the staff of the diatomite mine for their hospitality, administrative and logistic support during all fieldworks. This manuscript would be sloppy and less structured without the help of the editor Falcon Lang (London) and three reviewers: Fabrizio Marra (Rome), Lars van den Hoek Ostende (Leiden) and anonymous reviewer. We are thankful to them for their great corrections and the time taken for the review.
Keywords
- MN15
- Pliocene
- Pyroclastic density currents
- South Caucasus
- Vertebrate fauna