ИСТИНА

Cambrian problematic fossil Banffia, which is the only representative of the Banffozoa class-rank group, together with the Vetulicolia is commonly assigned to the Deuterostomia as a sister group of the Tunicata. However, none of over 300 specimens of Banffia having been described from the Cambrian Lagerstätten possess either gill slits or endostyle or any other distinct deuterostomian feature. On the contrary, it has an axially twisted vermiform body (10 cm long or less) divided into two equal in length sections, the presumable anterior one with the antero-ventral mouth surrounded by circlets and the posterior one with the terminal anus. A new Banffia specimen from the lower Cambrian Murero Lagerstätte of the Cadenas Ibéricas, Spain, due to its preservation by a clay mineral replacement, demonstrates further features of the body morphology. The posterior section is covered with numerous rhomboidal elements (20-25 μm in width) being organized in multiple ring-like bands. In addition to Si, Al, Fe, Mg, and Ti, which are typical of clay minerals, energy-dispersive X-ray spectroscopy reveals traces of calcium in the rhomboids suggesting their primary rigidity. The anterior section bears rounded elements of the same composition. Except for the body twist, the overall morphology of Banffia does not differ much from cuticles of coeval cephalorhynch worms. In turn, vetulicolians having a rigid anterior carapace, a segmented trunk, and mid-gut diverticulae show more similarity with the Anomalocaridida rather than with any deuterostomian group. Both the Banffozoa and the Vetulicolia are representatives of the early ecdysozoan radiation.