Vetulicolia

Vetulicolia is a group of bilaterian marine animals encompassing several extinct species from the Cambrian, and possibly Ediacaran, periods. As of 2023, the majority of scientists favor placing Vetulicolians in the stem group of the Chordata, but some continue to favor a more crownward placement as a sister group to the Tunicata. It was initially erected as a monophyletic clade with the rank of phylum in 2001, with subsequent work supporting its monophyly. However, more recent research suggests that vetulicolians may be paraphyletic and form a basal evolutionary grade of stem chordates.

==Etymology== The taxon name, Vetulicolia, is derived from the type genus, Vetulicola, which is a compound Latin word composed of vetulus "old" and -cola "inhabitant". It was named after Vetulicola cuneata, the first species of the group described in 1987.