Data from: The early elasmobranch Phoebodus: phylogenetic relationships, ecomorphology, and a new time-scale for shark evolution

Anatomical knowledge of early chondrichthyans and estimates of their
phylogeny are improving, but many taxa are still known only from
microremains. The nearly cosmopolitan and regionally abundant Devonian
genus Phoebodus has long been known solely from isolated teeth and fin
spines. Here, we report the first skeletal remains of Phoebodus from the
Famennian (Late Devonian) of the Maïder region of Morocco, revealing an
anguilliform body, specialized braincase, hyoid arch, elongate jaws and
rostrum, complementing its characteristic dentition and ctenacanth fin
spines preceding both dorsal fins. Several of these features corroborate a
likely close relationship with the Carboniferous species Thrinacodus
gracia, and phylogenetic analysis places both taxa securely as members of
the elasmobranch stem lineage. Identified as such, phoebodont teeth
provide a plausible marker for range extension of the elasmobranchs into
the Middle Devonian, thus providing a new minimum date for the origin of
the chondrichthyan crown-group. Among pre-Carboniferous jawed vertebrates,
the anguilliform body shape of Phoebodus is unprecedented, and its
specialized anatomy is, in several respects, most easily compared with the
modern frilled shark Chlamydoselachus. These results add greatly to the
morphological, and by implication ecological, disparity of the earliest
elasmobranchs.