This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

proofread

How elasmobranch species fared during and after the K-Pg mass extinction event

How elasmobranch species fared during and after the K-Pg mass extinction event
Diversification and diversity dynamics of all elasmobranch species. Bayesian estimations of speciation and extinction rates through time as inferred by PyRate using reversible jump Markov Chain Monte Carlo. Marginal estimates of speciation rates (A) and extinction rates (C) through time are shown as mean and 95% credibility intervals (shaded areas). The frequency of a sampled rate shift is computed within small time bins for speciation and extinction rates (B and D, respectively), with horizontal dashed lines indicating log-Bayes factors of 2 (bottom) and 6 (top). Sampling frequencies higher than log-Bayes factors = 6 indicate strong statistical support for a rate shift. Panel (E) shows net diversification rates through time (computed as the posterior difference between speciation and extinction rates through time). Panel (F) shows the number of species through time computed by summing up the lifespans of all species. The red vertical line indicates the Cretaceous-Paleogene extinction event. Time is millions of years. Credit: Science (2023). DOI: 10.1126/science.abn2080 . https://www.science.org/doi/10.1126/science.abn2080

A pair of researchers, Guillaume Guinot and Fabien Condamine, both with Université de Montpellier, in France, has looked at the impact of the Cretaceous–Paleogene (K-Pg) extinction event on elasmobranch species to learn more about survival of marine creatures during extinction events. In their study, published in the journal Science, the marine biologists collected and analyzed data for thousands of fossil species that were living during the Late Cretaceous–Paleocene era.

Scientists have learned a lot about what happened after the Chicxulub impactor crashed into the Earth approximately 66 million years ago. The violent impact and its aftermath led to widespread of approximately 55% to 76% of all the planet's creatures—including all of the non-bird dinosaurs. But most findings involve the impact on land-based ecosystems—much less is known about what happened to the sea life. In this new effort, the researchers focused their effort on just one subclass of cartilaginous fish—the elasmobranch—and how it fared in the aftermath of the K-Pg event.

Elasmobranch species include sharks, rays, skates and sawfish. To learn about what happened to them after the massive asteroid strike, Guinot and Condamine scoured information in datasets around the world describing elasmobranch fossil specimens that have been found and studied over the years. In particular, they were looking at to find patterns that might shed light on how they endured.

They found that the number of species of elasmobranch overall declined by over 62% following the asteroid strike, and some species of elasmobranch had than others. They found that rays did better than sharks—overall, 72% of ray species survived, while only 59% of sharks did.

More specific results included the discovery that rays that fed on shellfish did not fare well; neither did older species of sharks. Combined, they had an extinction rate of 72%. On the other hand, species that lived in the higher latitudes and lived over large geographic ranges not only had higher initial survival rates, but also recovered more quickly than other species.

More information: Guillaume Guinot, Global impact and selectivity of the Cretaceous-Paleogene mass extinction among sharks, skates, and rays, Science (2023). DOI: 10.1126/science.abn2080. www.science.org/doi/10.1126/science.abn2080

Journal information: Science

© 2023 Science X Network

Citation: How elasmobranch species fared during and after the K-Pg mass extinction event (2023, February 27) retrieved 15 April 2024 from https://phys.org/news/2023-02-elasmobranch-species-fared-k-pg-mass.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Ecosystem diversity drives the origin of new shark and ray species

64 shares

Feedback to editors