Tujiaaspis

Name meaning:

Shield of the Tujia people

Period of life:

~436 million years ago

Period:

Silurian period

Habitat:

Marine environment

Taxonomy:

Fish

Countries:

Silurian period Tujiaaspis | 3D Dinopedia

Thelodus

Guiyu

Tujiaaspis (~436 million years ago)

What the name means: “Shield of the Tujia people.” The genus name Tujiaaspis comes from the Tujia ethnic group living in southern China, where the fossils were discovered. Aspis is Greek for “shield.” The species name vividus means “full of life,” referring to the exceptional preservation of the fossils.

More than 400 million years ago, in the bottom waters of the ancient Earth, an unusual creature swam—Tujiaaspis, a jawless fish that possessed a remarkable feature: primitive paired fin-folds that may represent early precursors of vertebrate limbs. These animals lived in marine environments of the Early Silurian period. Tujiaaspis was a small but heavily built animal, reaching about 15 cm in length. Its body was flattened and covered with a rigid armor that protected the head and vital organs.

These animals belong to the enigmatic group Galeaspida, which are primarily known from their distinctive head shields. Specimens of Tujiaaspis, discovered in Chongqing and Hunan (China) in 2022, provided an exceptional opportunity to study the anatomy and evolution of early vertebrates due to their remarkable preservation.

They inhabited shallow marine environments and likely fed on small organisms by filtering water and bottom sediments. The head shield of Tujiaaspis was dense and heavy, serving as effective protection against predators. However, the most striking feature of Tujiaaspis is its fins—or more precisely, paired fin-folds—that extended along the sides of the body from just behind the head shield all the way to the tail.

This characteristic places Tujiaaspis in a unique position among armored jawless vertebrates. Previously, scientists believed that galeaspids, like modern lampreys, had smooth bodies without paired fins. However, Tujiaaspis demonstrates that early fish-like animals already possessed a developed fin system, which is a key insight into the evolution of fins and limbs in vertebrates.

According to paleontologists, these fin-folds may have allowed the animal to rapidly ascend from the bottom, helping it escape dominant benthic predators such as eurypterids (sea scorpions).

Tujiaaspis appears to represent a transitional stage in the evolution of paired fins, making it one of the most remarkable animals known from Silurian deposits.

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