Anostraca the Gondwana fragmentation closely echoes the current distribution of the order. Presently, Anostraca are found on all seven continents. Most of the extant genera have restricted geographical distributions. Only three genera are widespread across the remnants of the former supercontinent Pangaea: "Artemia", "Branchinella" and "Branchinecta", while the remaining genera are found only throughout former Laurasia. This suggests that much of the potential habitat in this supercontinent, now occupied by Anostraca, to have been unoccupied by ecologically similar species, or to have been inhabited by species with less adaptive ability. Studies have found Anostraca capable of rapid colonization and speciation. Anostraca
Lungfish current distribution of modern lungfish species reflects extinction of many lineages subsequent to the breakup of Pangaea, Gondwana and Laurasia. Lungfish have historically been referred to as salamanderfish, but this term more often refers to "Lepidogalaxias salamandroides". All lungfish demonstrate an uninterrupted cartilaginous notochord and an extensively developed palatal dentition. Basal ("primitive") lungfish groups may retain marginal teeth and an ossified braincase, but derived lungfish groups, including all modern species, show a significant reduction in the marginal bones and a cartilaginous braincase. The bones of the skull roof in primitive lungfish are covered in a mineralized tissue called cosmine, but