''Helicoconchus'' is a

microconchid The order Microconchida is a group of small, spirally-coiled, encrusting fossil "worm" tubes from the class Tentaculita found from the Upper Ordovician to the Middle Jurassic (Bathonian) around the world. They have lamellar calcitic shells, ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

that occurs in the Lower

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

of Texas. It forms small reef-like bodies of tubes branching from a common origin. The impunctate tubes are greatly elongated for microconchids and have occasional diaphragms with central pits. The tubes branch in two ways: budding from the tube wall and binary fission. They lived in shallow, normal marine environments.

References

Protostome enigmatic taxa Tentaculita Permian animals of North America {{permian-animal-stub