New research led by scientists at the University of Bristol shows how lepidosaurs, the most diverse clade of quadrupeds that includes lizards and snakes, evolved an astonishing variety of jaw shapes and He revealed what has brought him extraordinary success.
The rate of evolution of lepidosaur jaw morphology. Image credit: Ballell others., doi: 10.1098/rspb.2024.2052.
Lepidosauria is a clade of lizards, snakes, and tuataras with over 11,000 species, representing the most specialized group of today's tetrapods.
Since their origin over 240 million years ago, lepidosaurs have diversified into countless sizes and body shapes.
Among extant species, body size ranges over three orders of magnitude, typified by body lengths of approximately 1.7 cm. Sphaerodactylus Geckos and giant anacondas that are about 10 meters long.
The extreme size becomes even more dramatic when you consider extinct mosasaurs (up to 17 meters long).
Differences in body shape are reflected in different degrees of body elongation and reductions or modifications of limb elements in multiple lineages, and snake-like body shapes have evolved independently at least 25 times.
Similarly, lepidosaurs exhibit rich diversity in skull composition, shaped by the loss and gain of cranial bones over their evolutionary history and the acquisition of varying types and degrees of cranial motion.
As a result of this morphological diversification, Lepidosaurus conquered diverse ecological niches in most regions of the planet.
In a new study, University of Bristol researcher Antonio Barrel-Mayoral and his colleagues show that the evolution of jaw shape in lepidosaurs was influenced by ecological factors, including phylogeny (evolutionary relatedness) and allometry (scaling of shape with size). They found that it is influenced by a complex interaction of factors that go beyond science.
In terms of jaw shape, the snake was found to be a morphological outlier, exhibiting a unique jaw morphology. This is probably due to the snake's highly flexible skull and extreme mechanism that allows it to swallow prey many times larger than its head.
“Interestingly, we found that jaw shape evolves particularly rapidly in ecologically specialized groups, such as burrowing, aquatic, and herbivorous lizards. This may be due to evolutionary innovations in the lower jaw. “We suggest that this is the key to achieving these unique ecologies,” said Dr. Barrel-Mayoral. Said.
“Our research shows how lizards and snakes have evolved different jaw shapes to adapt to their wide range of ecology, diets and habitats, driving their extraordinary diversity. ”
This study highlights the important role of morphological innovations in promoting diversification in highly biodiverse groups such as lepidosaurs.
“The mandible, an important component of the vertebrate feeding apparatus, has been an important element in vertebrate ecological experimentation and adaptation.”
Looking ahead, the research team plans to further investigate the evolution of lepidosaur heads.
“The lower jaw is important because it works with the muscles that close the jaw to support important functions such as feeding and defense,” Dr. Barrel-Mayoral said.
“We are investigating the relationship between the shape of the skull and the placement of the jaw-closing musculature throughout evolution, and how this influenced the diversification of feeding mechanisms and habits.”
team's work Published today on Proceedings of the Royal Society B.
_____
antonio barrel others. 2024. Ecological factors in the evolution of jaw morphology in lepidosaurs. Procedure R. Soc. B 291 (2036): 20242052;doi: 10.1098/rspb.2024.2052
Source: www.sci.news
