Monday, April 4, 2011

C is for ... Coelacanth


Ugly little spud, as Ray Stanz might say; but the Coelacanth - the name is derived from the Greek koilos, hollow, and akantha, spine - is also something of a remarkable creature. Back in 1937, it was known to palaeontologists as a "missing link" between fishes and tetrapods: in other words, between aquatic and terrestrial life. It was also "known" back then to have died out, along with lots of other beasties, back in the Cretaceous Period - approximately 65 million years ago.

So it was a bit of a shock when, two days before Christmas a year later, one Marjorie Courtenay Latimer, of East London, South Africa, discovered in the trawl of her fisherman acquaintance Captain Hendrick Goosen a living breathing example of the genus. A museum curator, Latimer had an arrangement with Capt. Goosen that she could regularly inspect his catch and keep any items of interest - and it is probably fair to say no more interesting item ever turned up in his nets than the coelacanth. There wasn't even a Linnaean name for the coelacanth at the time, there being little call for one, so it became Latimeria chalumnae in honor of the curator who identified it. The fellow who only went and caught it earned no honor, since all he had in his nets was an ugly darn fish that stank: framing makes a big difference. In 1999, a second Latimeria species was discovered, in Indonesia. Both known coelacanth species are deepwater fish; the fossil record shows an abundance of coelacanths that dwelled in shallower waters, although by their nature fossils of deepwater taxa are hard to come across.

Often referred to as a "living fossil," the modern coelacanth is actually discernibly different from its fossil forebears, but still has enough taxonomic oddities that it grossly bears more resemblance to a Cretaceous fish than a modern one. It may yet face a long-delayed extinction, as deep-water trawling threatens its habitat; what might misleadingly be termed the anti-humanist faction among environmentalists may have a legitimate case in decrying the casual eradication of a species that has existed perhaps 20,000 times as long as we have. Of course, it's hard to be sure - relatively few animals become fossilized upon death, so the fossil record is an uncertain guide. Coelacanths are by no means the only "Lazarus taxon" - the reference is to John 11:1-46, notable for containing the shortest verse in the whole bible ("Jesus wept"); another biblical Lazarus is a subject for blogs otherwhen - and this is to be expected. Darwin's anticipation of a "missing link" between Man and Ape was, to put it mildly, optimistic given the patchiness of the fossil record overall; discoveries like Latimer's in 1938 reveal just how imperfect our knowledge is.

One consequence of the coelacanth's discovery was an energizing of a vociferous minority among biologists: the oft-ridiculed fraternity of cryptozoologists, whose focus is on species that don't officially exist. Although a select few of these feel their pulses quicken upon the triumphant verification of the existence of Laotian Rock Rats or Mountain Pygmy Possums, the greater number pursue more tabloid-friendly quarries: Bigfoot, Nessie, Mothman. Derided as pseudoscience, cryptozoology persists as a discipline because of a wealth of anecdotal evidence, a tissue-thin amalgam of ambiguous prints, spoors, and other traces... and finds like the Coelacanth. After all, if it could vanish for 65 million years, is it so hard to believe a Neanderthal clan might dwell in the Rockies and go unnoticed for a mere thirty millennia?

More on cryptids another time...

3 comments:

KarenG said...

Intriguing post! I feel like copying it out and reading it at my leisure so I can take it all in.

Laurie Peel said...

Good post! I listen to the "mysterious universe" podcast where they regularly explore cryptozoology. Looking forward to your future post on cryptids...

Heather Henry said...

Interesting creatures. We did a study of all of the bizarre creatures (that are known) in the ocean. It makes me a bit leary about swimming out there at this point in my life. The Angler fish is another strange one that I wouldn't want to encounter on a leisurely swim. I used to love swimming way out into the ocean when I was young, but then the information of all the creatures swimming beneath me wasn't as readily available as it is today. :)
I'm curious, what are you currently reading? I get the impression that you read a lot! :)
Have a wonderful day/evening!!