Shcherbakov D.E. 2025. Ecdysozoa are descendants of Articulata // Invert. Zool. Vol.22. No.1: 168–177 [in English].
Borissiak Palaeontological Institute, Russian Academy of Sciences, Profsoyuznaya St. 123, Moscow 117647 Russia.
Dmitry Shcherbakov: dshh@narod.ru ORCID https://orcid.org/0000-0003-4508-9259
doi: 10.15298/invertzool.22.1.11
ABSTRACT: A non-cladistic perspective on the origins and relationships of Annelida, Lobopoda, Arthropoda, Ecdysozoa, Crustacea, Insecta and Myriapoda. The deep similarity of jumping bristletails to syncarids show that insects originated directly from malacostracans. Myriapods are secondarily simplified descendants of early hexapods that lost the division of the body into thorax and abdomen due to the transition to a cryptic lifestyle. Entognathous hexapods model the initial stages of such ‘myriapodization’. The most basal euarthropods were dinocarids with grasping antennae but without walking legs. The most primitive Articulata are Polychaeta, and the group most similar to arthropods are Aphroditoidea. By analogy with myriapods and entognaths, lobopods and non-arthropod Ecdysozoa are interpreted as side branches from the dinocarid root of Arthropoda that simplified their body plans. The most primitive annelids were spintherid-like crawlers, which evolved from Anthozoa. Metagenesis of cnidarians reappeared as metamorphosis in polychaetes. Transformations of body plans occurred through heterochronies and heterotopies.
KEY WORDS: Polychaeta, Lobopoda, Dinocarida, Arthropoda, Crustacea, Insecta, Myriapoda, evolution, heterotopies, neoteny.