A new fossil indicates early sea species of ichthyosaurs gave birth headfirst.
According a study published in the Public Library of Science's journal One Wednesday the species an offspring of the Chaohusaurus perished while pro-creating, leading scientists to believe the process developed on land.
"The reason for this animal dying is likely difficulty in labor," Ryosuke Motani, lead study author and a paleobiologist at the University of California, Davis told LiveScience. "Obviously, the mother had some complications," Motani told LiveScience.
Motani theroizes the baby perished before coming out of the womb, while a labor complication ended the mother's life when giving birth to her second child halfway in and halfway out of her body.
"This land-style of giving birth is only possible if they inherited it from their land ancestors," Motani told Live Science. "They wouldn't do it if live birth evolved in water."
"The study reports the oldest vertebrate fossil to capture the 'moment' of live-birth, with a baby emerging from the pelvis of its mother. The 248-million-year old fossil of an ichthyosaur suggests that live-bearing evolved on land and not in the sea," Motani told e! science news.
Ichthyosaurs had a contour design fit for bodies of water with a long nose, and limbs that shrunk to mini fins so the species could swim its way through the water according to the Merriam-Webster definition.
The Ichthyosaurs also had a big fin, and big round eyes for capturing prey. They also conquered the ocean throughout the time period dinosaurs existed LiveScience reported.
The reptiles evolved from other reptiles who lived on land before diving into the water while the Triassic period was going on, 247 million to 251 million years ago.
The time period occurred after a large wipeout of water animals consumed 98 percent of sea life. Live Science reported. Seventy percent also perished onshore.
