[Rockhounds] Fossil discovery sheds light on the early evolution of animal nervous systems

[Kreigh Tomaszewski]

An international team of scientists has uncovered a fascinating piece of
the evolutionary puzzle: how the ventral nerve cord, a key component of the
central nervous system, evolved in ecdysozoan animals, a group that
includes insects, nematodes, and priapulid worms.

Their findings, published in a paper titled "Preservation and early
evolution of scalidophoran ventral nerve cord" in *Science Advances*,
provide valuable insights into the origins of these structures in the basal
Cambrian period.

The research team, comprising Dr. Deng Wang (Northwest University), Dr.
Jean Vannier (Université de Lyon), Dr. Chema Martin-Durán (Queen Mary
University of London), and Dr. María Herranz (Rey Juan Carlos University),
analyzed exceptionally well-preserved fossils from key Cambrian deposits.
These fossils include representatives of the early-evolving Scalidophora, a
subgroup of Ecdysozoa, offering a rare glimpse into the nervous system
architecture of ancient animals.

Ecdysozoans include arthropods (such as insects and crabs), nematodes
(roundworms), and smaller groups like kinorhynchs ("mud dragons") and
priapulids ("penis worms"). Their central nervous systems, which include
the brain and ventral nerve cord, have long intrigued scientists seeking to
understand the evolutionary relationships
<https://phys.org/tags/evolutionary+relationships/> between these groups.
https://phys.org/news/2025-01-fossil-discovery-early-evolution-animal.html