Is it an alien or an animal from the depths?

A variety of roots, a single stem, dozens of branching arms… are we interested in marine plants? No. crinoidscrinoids There are animals! they are classified between echinodermsechinodermsa phylum (or branchbranch) which consists of StarsStars of the seas, brittlestar, sea ​​urchinssea ​​urchinsat sea ​​cucumberssea ​​cucumbers, four news speciesspecies These curious animals are described in a recently published study invertebrate systematics Which solves the mystery of their kinship.

a biological puzzle solved

Most modern crinoids are winged stars, a group of mobile crinoids capable of crawling along the ocean floor due to the cirrus, a type of organ they also use to cling to themselves. substratesubstrate, The long arms that wing stars use to feed carry multiple barbules to capture plankton, and sometimes allow them to float when they beat them in rhythm! These dynamic species are present in a wide range of marine environments, even in the abyssal and surrounding cold waters.AntarcticAntarctic ,

The study, which has just been published, has studied the winged stars of this species. promachocrinus kerguelensis, the only one of its kind, that lives around Antarctica. researchers sequenced AshamedAshamed mitochondrial of a large number of samples. It turned out that there were eventually eight different species of crinoids, four previously proposed and four entirely new, grouped under this name! But how is this possible?

It happens that biologists have difficulty separating species that are morphologically very close, so these species are inadvertently grouped together under the same name. These are called cryptic species complexes, which scientists can mostly only identify through molecular analysis. With progress in the study of genomegenome On the invertebrate fauna of the waters of the Antarctic region, marine biologists are discovering more and more mysterious species. The researchers therefore established new morphological criteria that make it possible to separate almost all newly described species of feather stars from the genus Promachocrinuswhich will henceforth facilitate study for the purpose of inferring the truth BiodiversityBiodiversity of these extreme environments!