From Miki Malör’s Vampyroteuthis infernalis (left) shipboard photo by Carl Chun (right)
Via, Pharyngula, please watch this National Geographic clip on the Vampire Squid.
Careful viewers will note the “LF” bomb dropped liberally within the narration. Darren Naish recently skewered the “living fossil” moniker as a tag for the hirsute Sumatran Rhino regarded by others as a throwback to the days when large wool(l)y quadrapeds tramped across Eurasia.
“Living fossil” has been used to describe taxa with lengthy fossil records (sharks and crocodilians), phylogentically isolated taxa (Ginkgo) and taxa with previously widespread but now highly restricted distributions (Sphenodon), taxa with presumed primitive or highly conserved morphologies (Monotremes, horseshoe crabs), and taxa previously known only from the fossil record (Coelocanths, Metasequoia). Note that many of the groups listed may also fit some or all of the other various connotations.
Chuck D himself deployed the term In The Origin,
…All fresh-water basins, taken together, make a small area compared with that of the sea or of the land; and, consequently, the competition between fresh-water productions will have been less severe than elsewhere; new forms will have been more slowly formed, and old forms more slowly exterminated. And it is in fresh water that we find seven genera of Ganoid fishes, remnants of a once preponderant order: and in fresh water we find some of the most anomalous forms now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders now widely separated in the natural scale. These anomalous forms may almost be called living fossils; they have endured to the present day, from having inhabited a confined area, and from having thus been exposed to less severe competition. (Darwin 1859)
Darwin may be missing the mark here, life in fresh water lakes was apparently no impediment to the rapid radiation of Cichlids. The deep ocean has seemingly been a better archivist of living evolutionary history.
Neopilina was dredged from 3000 m, in one unsung evolutionary victory, validating and challenging platonic notions of mollusc evolution. Crinoids and brachiopods trade worn jokes filtered from the detrital rain of the upper-world. Vampire squid have held on to their old-time neocoleoid relijun. Archea, so named, bear their chronic burden at the interface of earth and sea. Or maybe not.
Evolution is a complex process played out within the spaces between innumerable overlapping breeding populations varying across space and time. There is no lockstep march forward, even if nucleotides do throb at an even pace. There is no more reason to believe that monotremes or tuataras ought to catch up to Quaternary morphologic standards, than to think our fellow Catarrhines should be learning how to use a salad fork correctly.