Chinese-led team reports first evidence of puberty in dinosaur-era reptile, offering new insight into sexual development

Name: Dinosaur fetus’ position inside Chinese egg fossil supports ancestral link with birds
Uploaded: 2023-07-01T08:00:17.000Z
Duration: 2 min
Description: Dinosaur fetus’ position inside Chinese egg fossil supports ancestral link with birds

Scientists from China, Japan and Germany studied extinct 240-million-year-old Triassic-period marine reptile Keichousaurus

Fossils show juveniles had rounded forelimb bone contours but by adulthood males had triangular contours while females kept rounded shape

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An artist’s rendering of the underwater dinosaur Keichousaurus. Researchers from China, Japan and Germany report that Keichousaurus males developed features distinct from females and reached sexual maturation through a process of puberty. Image: @Takumi

Victoria Bela

Published: 4:00pm, 1 Jul 2023

Some reptiles go through puberty, and an international team of researchers reports observing evidence of it in an extinct fossilised species for the first time.

The team from China, Japan and Germany who made the pioneering discovery published their findings in the peer-reviewed journal Current Biology last week, offering new insight into the sexual development of prehistoric vertebrate species.

Humerus and thin sections of two sexes of Keichousaurus. Image: Hefei University of Technology

Samples of an extinct 240-million-year-old Triassic-period marine reptile called Keichousaurus, which lived in what is now southwestern China, were the subject of the article.

Through examining sections of its bones, the research team discovered that Keichousaurus males developed features distinct from females and reached sexual maturation through a process of puberty, which allowed them to develop advantageous features for combat and mating, such as larger and more muscular forelimbs.

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Dinosaur fetus’ position inside Chinese egg fossil supports ancestral link with birds

Juveniles of the species have rounded forelimb bone contours, however by adulthood males had triangular contours while females retained the rounded shape.

After examining bone sections from 18 different individuals of the species, the researchers found a distinct stage in life in which the bone contours shift.