Monday, February 26, 2018

The Placoderms Have Left the Planet

When did the last placoderm die?
The standard answer is that all placoderms died by the end of the Devonian, in other words no later than 359 million years ago (MYA). It turns out this is (alas) pretty definitive.
One would think the placoderms were well-prepared to survive. They existed all over the world, in 334 named genera and no one knows how many species, and had evolved not only armor plate and terrifying choppers but also (in some species) developed claspers and modern intromittent sex, which took much of the randomness out of reproduction. (They also, in some species, invented real teeth.)  Dunkleosteus terrelli was the  king of the placoderms, and nothing in its time could mount any significant challenge to an adult of 7 to 8 meters.  (For cool information, see my page here.)

From the author's collection of my favorite placoderm, Dunkleosteus terrelli

But one might say that if extinction could happen to T. rex, it could happen to anyone, and the Devonian ocean ecosystem crumbled under a double extinction event (more accurately, two events separated by millions of years but close in geologic time.)   The first blow was the Kellwasser event. This came between the penultimate phase of the Devonian, the Frasnian, and the last phase, the Famennian. It kicked off about 375-374MYA (just as the famed Tiktaalik rosea was adapting to life out of water) and, according to Dr. Lauren Cole Sallan’s paper (see it here, cited below), caused “spectacular losses in marine diversity involving 1340% of families and 5060% of genera.”  It hammered such globally successful groups as trilobites, ammonites, and reef-building invertebrates, making a mess of the oceanic food web and to some degree making the existence of all marine species more precarious.  Just as D. terrelli (genus Dunkleosteus, family Dunkleosteidae, order Arthrodira, class Placodermi) and its kin were congratulating themselves for dodging this train of destruction, they met the ecological bulldozer called the Hangenberg event, 359MYA. This calamity wiped out the placoderms for good and left the oceans open for the rise of two now-dominant lineages, the ray-finned bony fishes of the class Actinopterygii and the sharks and rays of the class Chondrichthyes.   (The sarcopterygians (coelacanths, lungfishes) and the agnathans (lampheys and hagfishes – the Greek name means “disgusting as hell,” or at least it should) also snuck through.)  See NOTE below for a little more information on these extinctions.
There are, in sources like, claims that one or two species of placoderms escaped the bottleneck of end-Devonian times and made it into the Carboniferous, though they didn’t last long.  This is now considered highly suspect at best and very likely false. Raising the question sparked a good discussion in the Devonian Period FaceBook group, and the scientists who weighed in, including Dr. Sallan and Dr. Andrew Bartholomew, are quite certain the claims of placoderms from above the black shale layer which ends where the Devonian ends were based on material that was misidentified or reworked. (I wonder if it was more the latter than the former: it’s hard to imagine chunks of placoderm armor in any strata not being identified, either at the time of collection or in later reviews.) Dr. John Marshall, a Professor at the University of Southampton, pinpointed the sites as lying on the Greenland-Scotland Ridge, with one site in each of the nominate landforms, and posted that he and others had looked at the areas involved without finding any evidence of placoderms.
So that was it for the placoderms. Having crept innocuously into the record in the late Siluran period, introduced long-lasting evolutionary concepts and innovations (although the sharks apparently lost their stashes of placoderm porn and had to invent clasper-based sex all over again), and ruled most of the 60-million-year Devonian, they vanished from the stage, gone but not forgotten. 

Numerous sources including:   
Sallan, Lauren, and Coates, Michael (June 2010). "End-Devonian extinction and a bottleneck in the early evolution of modern jawed vertebrates," Proceedings of the National Academy of Sciences. 107 (22): 10131–10135. doi:10.1073/pnas.0914000107. PMC 2890420. PMID 20479258.
Balter,Vincent, et al. (2008).  “Record of climate-driven morphological changes in 376 Ma Devonian fossils,” Geology, 36(11):907.
Maisey, John G. and Maisey, John. Discovering Fossil Fishes : Your Guide to the Wonders of Prehistoric Ocean Life (1996). Henry Holt.

NOTE: The Kellwasser event (actually a series of events with a variety of possible causes including vulcanism and extraterrestrial impacts) opened about 375 MYA and, by some reckonings, lasted almost up to the Hangenberg event, 359MYA. The latter planet-wide ecological shift, possibly caused by the combination of falling sea levels and the effects on atmospheric and oceanic chemistry from the burgeoning success of terrestrial plant life, changed the oceans so drastically it brought the Age of Fishes to a close and drove into extinction 97 percent of known vertebrate species (remember, these were almost all fishes) with it.

Tuesday, February 20, 2018

The Latest New Shark is a Resurrected Species

It's very hard to keep up with the sharks. In my adult lifetime we have gone from about 300 species to 450 and climbing. Now the Atlantic sixgill shark, up to 1.7m long, has been proven distinct from those in other oceans thanks to genetic analysis. The species Hexanchus vitulus was actually proposed in 1969, later dropped in a consolidation with other sixgills, and has now been resurrected in an example of what genetic analysis can add to the traditional classification by physical characteristics.  Here's the paper

Sunday, February 18, 2018

Dogman: the Mythical Beast that Chomped Bigfoot

Bigfoot, real or not, is the undisputed king of America's reported unknown animals, aka "cryptids."  Since the filmed encounter from California in 1967 (strongly argued to be a hoax, but from a public interest point of view, it almost doesn't matter), nothing reported in North America has consumed more ink, videotape, and RAM than the big guy. The chupacabra mythos carved out a niche, and the lake monsters like Champ and Ogopogo haven't gone away (assuming they were there), but cryptozoologists and lovers of the unknown are focused overwhelmingly on Sasquatch.  
Enter the Dogman.  This alleged denizen of the north-central U.S., especially the woods of Michigan and Wisconsin, is not going to knock Bigfoot off his tree stump, but it's the first cryptid since myth and image merged after the 1995 movie Species to create the chupacabra that could take a bite out of the Bigfoot-branded pizza of popularity.  
Dogman stories in Michigan have been traced as far back as 1887 (although Bigfoot fans will point out that still makes it a juvenile in cryptid terms).  Something similar from Wisconsin, which hit the newspapers beginning in 1992, was known for a long time from the location of its first reports, so the Beast of Bray Road has become part of the same concept. The Dogman and similar creatures are based on dozens of reports, including some hoaxes but, as Linda Godfrey has documented, a lot from sincere people, some of them flat-out scared by the encounter.
Physically, one can think of the Dogman as a very large werewolf that never goes back to human.  It's not claimed to transform into anything, although running on all fours has been reported.  Running like a wolf seems to be part-time, though: Dogman is very much a habitual biped, often over 2m tall.
The legend  really took off with Linda Godfrey's 2003 book The Beast of Bray Road: Tailing Wisconsin's Werewolf
The Beast got more popular with the release of its "based on actual events" movie in 2005. (As B-horror films go, it wasn't bad at all.)
Godfrey certainly thinks there is somethign worth looking into, as she has produced another book on the creature, Real Wolfmen: True Encounters in Modern America, and two broader books on monsters.   Overall, her books are too credulous for my taste, but American Monsters and Monsters Among Us collect a lot of interesting critter reports I'd not read before, so they are at the least fun reading.  You can check out her website at The Bray Road Beast has at least one other website, one that suggests reports have nearly ceased and the creature behind them has moved on. 
My favorite fictional universe, Jim Butcher's Dresden Files, got in on the act in 2018 with a graphic novel, Dog Men. Butcher's wizard Harry Dresden hears of an attack by one (in Mississippi, where I don't think they've ever been reported, but we're already into wizards and magic, so ok) and assumes they are werewolves. Native American wizard Listens-to-Wind explains the "wolf people" have always been there and are intelligent flesh-and-blood creatures, not magical (although they seem able to sense magic, and they really, really hate ghouls).  Given Butcher's large nationwide readership, this will no doubt give the cryptid's popularity another boost.
Is there a huge bipedal creature with dog ancestry? No.  
Canid bodies are wholly unsuited to bipedalism: trained show dogs are impressive but clearly unnatural and can't maintain a two-pawed walk for any longer than it takes to hold a stage act on largely flat surfaces. A line of evolution from known canids to a bipedal creature is, by itself, not a crazy idea, but it would have to be a long line, with changes taking hundreds of thousands of years at least if humans are any guide. We don't have a scrap or trace of fossils of all this. Some cryptozoologists suggest the reports are mistaken sightings of Bigfoot, but then you have the same problem, once removed as it were. Leading cryptozoologist Loren Coleman suggested a link to the cryptid known as the shunka-warak'in (think of a wolf on steroids), but that hasn't been established either (although it intrigues me, something other American land cryptids generally don't). 
So to me, the Dogman and his ilk are a modern American myth, the latest to emerge on a nationwide stage in a nation that has always loved monsters in folklore, film, and literature. As with Bigfoot, it is more likely sincere witnesses are mistaken than that something looking like a wolfman exists. (Bigfoot is on a bit better ground here, since we know there are large bipedal primates (us)).  So enjoy. Just don't tell me the Dogman exists unless you've got one on a leash. 

Tuesday, February 06, 2018

Awesome, SpaceX.

My holy trinity of the three coolest launches I've ever seen: Apollo 11 (was there), first Space Shuttle (on TV, though I was there for the landing) and this one (TV, unfortunately). Just an incredible accomplishment. Congratulations to Elon Musk, Gwynne Shotwell, and countless other people, not just for technical success, but for being able to dream big in a risk-averse world.

Monday, February 05, 2018

Book review: Mystery Creatures of China

David C. Xu
Coachwhip, Greenville, OH, 2018
This is the first book ever on cryptids of China, and it’s magnificent. David Xu, a Beijing-based writer and editor, has pulled together story threads from ancient legend to modern sightings from all over China, and in partnership with Coachwhip has provided a sumptuously illustrated compendium of creatures from the famous (e.g., the yeti) to creatures virtually unheard of in the West (e.g., the tuoniao, a large bird reported from Sichuan province). The book offers short-to-medium-length accounts split into aquatic, humanoid, carnivorous, herbivorous, reptilian, and winged cryptids. Even as a longtime reader of cryptozoology, I found surprises on every page, with probably two-thirds of these creatures completely new to me. China, even in the 21st century, offers many unknown-animal-reports, and it would be surprising if none pointed us to new species, either extant or recently extinct, in that vast land.

The author is careful to note than one possible explanation for most cases include rumor, folklore, and so on.  This is pretty easy to apply to creatures such as a bull with amphibious qualities and a fin on its back (reminiscent of the “water horse” only using a different animal.) Several variations in color or location for lions, tigers, etc. are likely odd or wayward examples or small populations of known species (which makes them no less interesting).  Some of these cases are genuinely puzzling. What to make a of a large hoofed animal a bit like a deer or goat, but sometimes reported as scaled and with a single horn? Just a unicorn-ish legend? Maybe, but it’s been seriously reported for over 2,500 years and is still being seen, and we know of animals whose two horns are well aligned to be seen as one from the side.  (The author displays his knowledge of paleontology here by suggesting several presumed-extinct mammals that might match the sometimes-inconsistent descriptions.) Or, for a more plausible animal, take the hengziniao, a bird that appears to be a very large owl that makes startling calls, one described as “heng-heng.”  There are not many reports, but nothing about it seems unrealistic.
The illustrations are frequent and often marvelous, ranging from ancient woodcuts and sculptures to modern photographs.  A special addition, most useful for those of us who do not know Chinese geography well, is the outstanding map section. 
I offer two nitpicks, both concerning lake-dwelling cryptids. One is that I wish the author had managed to get permission to publish even one image from the numerous photographs and videos he writes  have been taken of the more famous lake creatures. Reported photographic evidence is frustrating to read about when one cannot see any of it. The other is that, in introducing us to particular lakes, the author gives only general descriptions like “large” and does not mention numbers for the area, volume, or depth of the lake.
These are small deficiencies in a book that is beautiful, well-written, intriguing, and most definitely fun.  There is plenty here for the zoologist, the folklorist, and the historian alike.