This colorful creature named Balhuticaris voltae swam in the Earth’s oceans from the Cambrian period approximately 506 million years ago.
According to the study published in the journal iScience, the arthropod would have measured 24.5 cm in length, which makes it one of the largest Cambrian arthropods and the largest bivalve arthropod known to date, unseating the closest such as Nereocaris exiles and Tuzoia.
Balhuticaris voltae would have belonged to a group of Cambrian arthropods that possessed bivalve shells and superficially resembled shrimp.
“The Cambrian bivalve arthropods are a group of arthropods characterized by their cephalothoracic bivalve shells. Many bivalve arthropods are known only from isolated shells, but fossils with soft tissue preservation are revealing an increasingly complex polyphyletic group, mainly comprising the stem group euarthropoda Isoxyidae and Hymenocarina ”, explain paleontologists Alejandro Izquierdo-López. and Jean-Bernard Caron of the University of Toronto.
“With 30-40 known species, hymenocarines are the most diverse of the two groups, but their position in early arthropod evolution has been widely debated,” the authors continue.
Its body was quite striking, being extremely elongated and multi-segmented with 110 pairs of homonymous biramic limbs. Its shell had a bow-like appearance; it covered only the most frontal section of the body but extended ventrally beyond the legs.
“With a total of 110 postcephalic segments, Balhuticaris voltae has the highest number of segments recorded among Cambrian arthropods,” the researchers said. “Multi-segmentation (more than 20 segments) is widely present in Cambrian arthropod groups, such as jianfengiids, marrelomorphs, and in multiple trilobites.”
Researchers discovered several specimens in Marble Canyon of the famous Burgess Shale, a Cambrian-age fossil field in Canada. “ Balhuticaris voltae is one of the largest completely preserved animals from the Burgess Shale and the Cambrian,” the scientists concluded.
Referencia: Alejandro Izquierdo-López & Jean-Bernard Caron. Extreme multisegmentation in a giant bivalved arthropod from the Cambrian Burgess Shale. iScience, published online June 25, 2022; doi: 10.1016/j.isci.2022.104675
