Climatic controls on the ecological ascendancy of dinosaurs

Author(s)

Dunne, Emma M. ; Farnsworth, Alexander ; Benson, Roger B. J. ; Godoy, Pedro L. ; Greene, Sarah E. ; Valdes, Paul J. ; Lunt, Daniel J. ; Butler, Richard J.

• Document type: Journal article
• Source: Current Biology; v. 33, n. 1, p. 14-pg., 2023-01-09.

Abstract

The ascendancy of dinosaurs to become dominant components of terrestrial ecosystems was a pivotal event in the history of life, yet the drivers of their early evolution and biodiversity are poorly understood.1-3 During their early diversification in the Late Triassic, dinosaurs were initially rare and geographically restricted, only attain-ing wider distributions and greater abundance following the end-Triassic mass extinction event.4-6 This pattern is consistent with an opportunistic expansion model, initiated by the extinction of co-occurring groups such as aetosaurs, rauisuchians, and therapsids.4,7,8 However, this pattern could instead be a response to changes in global climatic distributions through the Triassic to Jurassic transition, especially given the increasing evidence that climate played a key role in constraining Triassic dinosaur distributions.7,9-16 Here, we test this hypothesis and elucidate how climate influenced early dinosaur distribution by quantitatively examining changes in dino-saur and tetrapod "climatic niche space"across the Triassic-Jurassic boundary. Statistical analyses show that Late Triassic sauropodomorph dinosaurs occupied a more restricted climatic niche space than other tetrapods and dinosaurs, being excluded from the hottest, low-latitude climate zones. A subsequent, earliest Jurassic expansion of sauropodomorph geographic distribution is linked to the expansion of their preferred climatic conditions. Evolutionary model-fitting analyses provide evidence for an important evolutionary shift from cooler to warmer climatic niches during the origin of Sauropoda. These results are consistent with the hypoth-esis that global abundance of sauropodomorph dinosaurs was facilitated by climatic change and provide sup-port for the key role of climate in the ascendancy of dinosaurs. (AU)

• FAPESP's process: 22/05697-9 - Using comparative methods to fill the gaps of Crocodylomorph macroevolutionary knowledge
• Grantee: Pedro Lorena Godoy
• Support Opportunities: Scholarships in Brazil - Post-Doctoral