It has a torpedo-shaped body with no fins. Nuucichthys lyoncocephalus It was the first molluscan vertebrate discovered in the Great Basin of the United States.
Nuucichthys lyoncocephalus It was a pelagic organism with limited swimming ability. Image courtesy of Franz Anthony.
Nuucichthys lyoncocephalus It lived in the Cambrian oceans between 505 million and 500 million years ago.
This ancient animal had a finless, torpedo-shaped body with many of the characteristics characteristic of vertebrates.
It is one of only four species that document an early evolutionary stage in the vertebrate lineage.
“discovery Nuucichthys lyoncocephalus “This discovery is a valuable contribution to early vertebrate evolution and biodiversity, as few organisms of this type have been found in Cambrian fossil sites (such as southern China, the northeastern United States, and British Columbia),” said paleontologists Rudy Leroy Aubril and Javier Ortega Hernández of Harvard University.
“Early vertebrates began to have large eyes and a series of muscle blocks called myotomes, which are very recognizable in fossils.”
The subject of the study Nuucichthys lyoncocephalus It is a single partial fossil found in the Marjum Formation in the House Mountains of western Utah, USA.
“Nuucichthys lyoncocephalus “This is the first soft-bodied vertebrate to be discovered in the Marjum Formation of the American Great Basin,” the paleontologists said.
They also found that despite its overall similarity to larval fish (with primitive gill-like cavities), the new species lacked fins, limiting its swimming ability.
“But all these features clearly show similarities to vertebrates,” Dr. Lerosay-Aubril said.
“It's such an early stage in vertebrate evolution that we don't have any bones yet, which is why these fossils are so rare.”
The authors speculate: Nuucichthys lyoncocephalus It probably lived high in the ocean's water column.
Because of this, and because they lacked biomineralized parts like bones or shells, they tended to deteriorate and decay quickly after death, which explains why very little fossilization occurred.
“What's interesting about this new species is that without fossils it's hard to understand how the morphology evolved from an invertebrate to a vertebrate form, but this new fossil tells us a little bit about that,” Dr Ortega-Hernández said.
Discovery Nuucichthys lyoncocephalus It has been reported paper In the journal Royal Society Open Science.
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Rudy Lerozay Aubril & Javier Ortega Hernández. 2024. A long-headed Cambrian soft-bodied vertebrate from the Great Basin region of the United States. R. Soc. Open Science 11(7):240350; doi: 10.1098/rsos.240350
Source: www.sci.news
