Letter G: Glaciation

A glacier is ice, formed by layer upon layer of snow that begins to flow under its own weight. It may end on land, in which case it can form the headwaters of a river or (as in the dry valleys of Antarctica) simply sublime into very dry air. It begins, however, in an area that is glaciated, or covered with compacting snow. That area may be a small as a glacial cirque or as large as Antarctica.

This is Antarctica, but at one time much of North America looked like this. Photo Source

Continental-scale glaciations today are limited to Antarctica and Greenland. But 18,000 years ago, much of North America to south of the Great Lakes and Eurasia into the Alps and Carpathians was covered by a solid sheet of ice. The Himalayan glaciation was also much more extensive than is the case today, and the Rockies were also covered with ice. In fact,  all mountain glaciations were more extensive then, including the Brooks and Alaska Ranges in Alaska.

Interestingly, while New York State, the Great Lakes, and northern Europe were covered with mile-thick ice, interior Alaska and large parts of northern Asia remained ice free, a cold steppe that supported mammoths, long-horned bison, and horses. The Bering Sea was mostly land, due to lower sea level, and many scientists believe that the first inhabitants of North America moved from Siberia to Alaska with no idea that they were entering a new continent. But there is no evidence that there has ever been glaciation where I live, in Interior Alaska. It was and is too dry. Only the frozen bones of long-extinct animals preserved in permafrost are left to tell the tale.

 

Weekend Writing Warriors, Tourist Trap

It’s Sunday again, time for Weekend Writing Warriors (click the logo above) and Snippet Sunday (click the logo below.) As I said last week, snippets will be random for a while, and this one is from my second published book, Tourist Trap. The setting is Falaron, a planet terraformed to resemble Earth during the Pleistocene, and the animal is a flat-headed peccary, common in Pleistocene North America and considerably larger than any peccary now alive. A herd has invaded the travelers’ campsite while they slept, and a young sow has gotten her head caught while trying to get the last of a bucket of honey.

They dived in from opposite sides of the mad, blind creature, shoulders brushing as Timi’s weight collapsed the animal’s hindquarters and Roi landed atop the shoulders. The peccary’s frantic squeals, amplified and directed by the bucket, reverberated in Roi’s ears, and its odor was rank in his nostrils. Its coat was as rough and bristly as it looked, harsh against his hands and arms.

It wasn’t totally blinded, Roi saw. The handle if the bucket was caught behind the sow’s ears, and the eyes were set so high in the skull that he could see them, rolling wildly, from where he lay. But it could not see ahead of itself. Roi opened his mind and used his physical contact with the animal to force his own awareness into the animal mind, controlling its struggles and he had quieted the three horses during the storm. “Hang on to the rear legs until I tell you to let go,” he told Timi, and began struggling to get the handle of the bucket back over the flathead’s ears.

Tourist Trap is available in hard cover, soft cover, and ebook at Amazon and Barnes and Noble. For some reason I can’t get through to Amazon that I’ve lowered the ebook price to below $5, so the Kindle version is ridiculously expensive relative to the Nook or the publisher price. Complain to Amazon; they aren’t listening to me.

Next weekend Horse Power will be free on Amazon, and I’ll have a little more of the stampede.

Waking the Baby Mammoth: DVD Review

In the spring of 2007 Yuri Khudi, a reindeer herder in northwestern Siberia, found a baby mammoth carcass, still frozen and remarkably complete, lying on the snowy tundra. Scientists named her Lyuba (little love) after Yuri’s wife – who did not appreciate the honor! Lyuba’s discovery and the scientific investigation that followed became the subject of a National Geographic program, first aired roughly two years after her discovery, and later made available as a DVD.

From a scientific point of view, the DVD is excellent. Certainly some of the scenes of the finding, disappearance and re-finding of Lyuba must have been re-enacted, but not obtrusively so. The long-distance travel, tomographic investigation and subsequent tissue sampling of Lyuba appear to have been photographed in real time, and give a much better idea of how a frozen mummy can be investigated than is generally available. Some of the discoveries included the definite identification of heat-producing brown fat in Lyuba’s hump, her age at death (only about a month) and that she died, probably by drowning, in excellent health.

The reindeer herder Yuri was able to be present at part of the autopsy, and a highlight of the DVD is Nenets culture as the scientists investigating Lyuba stayed with Yuri’s family as they examined where she had been found. The problem of how her body reached the surface of the tundra without thawing or decay is still unsolved.

As usual in National Geographic DVDs, the computer graphic imaging of mammoths in their Pleistocene setting consists of a relatively few clips repeated several times. To some extent this is offset by a series of charming vignettes of Lyuba against modern backgrounds – wandering the museum, appearing to scientists relaxing in modern settings, and interacting with Yuri’s reindeer.

Lyuba is featured a current exhibition touring the USA and the world from the Field Museum. She is just finishing a visit in Hong Kong.

If you like Pleistocene mammals, this is definitely a program to see. Of course I’m prejudiced, since I used mammoths, among other Pleistocene mammals, in Tourist Trap.

Arctic Dinosaurs: DVD Review.

Dinosaurs in the Arctic? I live in Alaska and know several geologists, so I heard about the dinosaur bones on the North Slope almost as soon as they were rediscovered. My first reaction, years before this DVD was made, was, “what was the latitude at the time the dinosaurs lived there?” After all, the fossils were about seventy million years old, and plate tectonics has reshaped the continents and oceans considerably since that time. At first, the answer was “it hasn’t been checked yet,” but when it was checked, it turned out that the fossil location was even closer to the pole that it is now: probably at around latitude 80°.

Rediscovered? Turns out the bones were discovered clear back in 1961 by a Shell Oil geologist named Robert Liscomb. He sent them back to Shell, but when he was killed in a rockslide the following year, the bones were forgotten in the Shell archives. It was not until well into the 1980s and renewed interest in petroleum on the North Slope that the bones were sent to the Geological Survey, where they were first identified as being from a dinosaur.

None of which answers the question of how dinosaurs managed to live at a latitude where there was no sunlight for four months of the year, and no night for another four.

This DVD focuses on two questions. First, it examines the digging of a tunnel into the permafrost along the banks of the Colville River in an effort to find bones that were not broken up by freeze-thaw cycles. Second, it speculates on how dinosaurs managed to survive so near the pole. Were they migratory? What did they eat, especially in the winter? What ate them? What was the climate like? What does the discovery of dinosaurs at such a high latitude suggest about whether dinosaurs, like their bird descendants, were warm-blooded?

Certainly there is evidence for a climate far warmer than today’s on the North Slope, even though the latitude was higher. There is no evidence for sea ice that far back, and an open ocean would have made for a much warmer climate. But plants could not have grown without sunlight, so what did the herbivores eat? Moose today winter on bark and twigs – they certainly nipped all the buds off of my Amur maple last winter, and when I had a crab apple tree, it got smaller every year as the moose nibbled its twigs over the winter. Could dinosaurs have done the same?

Although this video does have some dinosaur animation of reasonable quality, it is of interest primarily for what it reveals about dinosaurs and their fossils. It was originally a TV program, from PBS on Nova. Get it for information, rather than entertainment.

The Essential Dinosaur Pack Disc 2: DVD Review

This disc, although it has a copyright date of 2008, is a collection of TV programs originally aired between 2003 and 2008. Thus none are really up to date.

“The Mystery Dinosaur,” from 2006, deals with the discovery of  “Jane.” This fossil has been variously identified as a Nanotyrannus and a juvenile Tyrannosaurus Rex. The program is primarily about the argument, which could date it, but as far as I can tell, the argument has never been resolved. Thus the program is still fairly current, though it is more science than entertainment.

“Dinosaurs: Return to Life” deals with the observations that the differences between dinosaurs and birds appear to be due to a relatively small number of mutations. Could birds be “reverse bioengineered” to produce something like dinosaurs? Would we really want to?

The four-program series “Dinosaur Planet” first aired in 2003, and unlike the rest of the programs in this set, it is definitely intended to be entertainment. Each of the four episodes focuses on one or two individual dinosaurs and follows them through a period of their lives. Each episode also covers something that is important or intriguing in the fossil record, and links back to that record. Thus “White Tip’s Journey,” featuring a Velociraptor,  suggests one explanation for the famed (real) fossil of a Velociraptor locked in a death struggle with a Protoceratops.

“Alpha’s Egg,” featuring the large sauropod Saltasaurus and the medium-sized predator Aucasaurus,  is based on the discovery of  a Saltasaurus nesting ground,  fossilized in Patagonia.

Pod of “Pod’s Travels” is based on a Pyroraptor,  a European raptor genus. The episode includes the natural hazards (earthquake, tsunami) that made occasional travel between the islands that made up Europe 80 million years ago possible. The focus of the program is on the dwarfing effect that islands tend to have on species. Pod is a Gulliver among Lilliputians when a tidal wave sweeps him to a much smaller island.

“Little Das’ Hunt” follows a juvenile Daspletosaurus  (an earlier close relative of Tyrannosaurus Rex) learning to hunt, and a herd of Maiasaura. The episode is based on a group of Daspletosaurus and Maiasaura found fossilized together in Montana, but the evidence for the kind of pack behavior shown in the episode is scanty and controversial.

Obviously there is a good deal of imagination going into the behavior, color, feathers or lack of them, musculature and behavior of all of these dinosaurs. Here I want to mention three, because they struck me so strongly.

The first is the underline of the creatures portrayed.  Theropod dinosaurs did indeed have a bone jutting back from the pelvis. However, the velociraptors are shown as having this bone stick out of the body, covered by a narrow wedge of tissue. It seems to me that this arrangement would be very susceptible to breakage, and that evolution would have reduced the length of the bone fairly fast. It makes much more sense that the tail and the posterior part of the belly were much deeper, with the projection buried in muscle. In fact a mummified hadrosaur had exactly this conformation, with a tail much deeper than anyone expected. Why not Velociraptor?

Second is the behavior of prey dinosaurs. Granted they didn’t have much brain, but instinct is also guided by evolution. Threatening a predator with teeth adapted to munching relatively soft leaves, and exposing the vulnerable neck in the process, does not make sense. Kicking (recent work has shown sauropods had vicious kicks) or tail swipes are far more reasonable for the big plant-eaters. This bothered me as far back as the Disney dinosaurs in Fantasia, when the stegosaurus turns to try to threaten T. Rex with its tiny mouth, instead of lashing out with its spiked tail. Now Disney may be forgiven – after all, Fantasia came out in 1940. Between making his dinosaurs animatable by artists drawing each cel by hand and the paleontological knowledge of the day, he did a respectable job even if his sauropods did have necks like snakes and his characters never actually lived at the same time. But that stegosaurus is pure theater, and Discovery Channel should have known better.

The third is grass. There is now some controversy over whether dinosaurs and grass coexisted, but the amount of grass shown is almost certainly incorrect.

Overall evaluation? Watch, but don’t believe everything you see. This DVD has a lot of creative interpretation, some of it almost certainly wrong.

The Essential Dinosaur Pack Disc 1 (DVD Review)

This set of two DVDs, although the cover has a date of 2008, in fact combines episodes originally aired on the Discovery Channel from 2001 to 2008. The first disc contains four episodes:  Valley of the T. Rex (2001), T-Rex: New Science, New Beast (2006), When Dinosaurs Roamed America (2001) and Utah’s Dino Graveyard (2005). Keep the true dates straight, because our interpretation of dinosaurs is changing rapidly, and the episodes at times seem to contradict each other. None of the interpretations are truly currant, or represent today’s ongoing controversies.

This DVD focuses on the processes of finding, unearthing and interpreting fossils, with only minor clips of computer generation of the living animals. It will be of more interest to budding paleontologists than to those looking for entertainment.

Valley of the T-Rex looks at the idea put forward by Jack Horner that T-Rex was primarily a scavenger, not a predator. The idea is hardly new, and is far earlier than the discovery of T-Rex’s tiny arms – Wiley Ley proposed it as a science article in the April 1943 issue of Astounding Science Fiction. I really doubt that there is any such thing as a pure predator or a pure scavenger. Any predator will scavenge a fresh kill, and any scavenger will kill an animal down and helpless, if only by eating it. Like the short-faced bear, T-Rex may have used its impressive size to intimidate other predators off their kills, but that doesn’t mean it never killed.

T-Rex: New Science, New Beast is more balanced, mentioning that how T-Rex fed is controversial but not getting into the controversy. Rather, it summarized new (as of 2006) methods of investigating dinosaur fossils. This included learning how to tell how old fossil dinosaurs were at death (which led to the discovery of the fantastic teenaged growth spurt of T-Rex and the relatively young age (29) of Sue, the largest T-Rex found.) At least one dinosaur was sexed, though the technique only works with pregnant (with eggs) females. Study of locomotion in modern animals has been applied to dinosaur skeletons, suggesting a lower top speed for full-grown T-Rex than was previously estimated. The episode also mentioned the discovery that some fossil bone had collagen, study of T-Rex bite strength, and the discovery of feathered theropods, leading to the possibility that T-Rex juveniles, at least, had downy feathers.

When Dinosaurs Roamed America goes through the history of dinosaurs, using an American location to spotlight each time period. Remember this segment, and the computer animated clips included, is eleven years old in 2012.

The video starts with New York (Permian-Jurassic, first dinosaurs, early opening of the Atlantic.) It then moves on to Exeter Township, PA (Triassic-Jurassic boundary, theropod-sauropod split.) Utah was a savannah 150 million years ago, wandered over by giant sauropods, their predators, and the smaller herbivorous dinosaurs that survived at their side. New Mexico 90 million years ago was a tropical swamp, with an explosion of flowering plants and broadleafed trees. The notorious K-T (Cretaceous-Triassic) boundary and the final extinction of the dinosaurs is investigated in South Dakota. The video is not bad, but dated.

The final program, Utah’s Dino Graveyard, covers a single location with a huge number of dinosaur fossils of a single species. Falcarius Utahensis was a strange beast even by dinosaur standards, as are most of its Therizinosaurian relatives. It is one of the earliest of a group that evolved from raptor-like carnivores to big-bellied but still relatively upright herbivores. This does happen – all dinosaurs, even the huge sauropods such as Apatosaurus evolved from early ancestors that ran on two legs and preyed on insects. More recently, the giant panda seems to be a bear that has embraced a diet of bamboo.

The real question is, what killed large numbers of the same species? Their preservation seems to be due to the fact that they all died near ancient springs, with rock from the spring deposits forming a cap that preserved their bones, but could the spring also have played a role in their deaths?

In general the computer graphics are adequate but not inspired, and at times show behavior I have doubts about — but I’ll save that critique for the second disc.

Dinosaurs Inside and Out: DVD Review

This is actually a reissue of programs aired on the Discovery Channel in 1997, though the DVD has a 2009 date. The package date is very misleading, as both the facts given and the computer animation are 15 years old – before the first airing of Walking With Dinosaurs. The computer animation, in particular, is very poor, and I would certainly not buy this DVD to watch the dinosaurs!

The DVD includes four 1-hour programs: Renaissance of the Dinosaurs, Land of the Giants, The Killer Elite, and And Then There Were None. In order, they deal with the public fascination with dinosaurs, the large herbivores, the two-legged killers such as T-Rex and raptors, and the extinction of the dinosaurs.

Luckily, the program concentrates not on the videos, but on the science of paleontology. Even that is a bit dated in describing what is known about dinosaurs, though the finding, excavating, packing and cleaning of specimens is worth watching for budding paleontologists. So is the history of our fascination with dinosaurs, including more than the usual information about how our views about dinosaurs have changed since the Crystal Palace reconstruction and the dinosaur wars between Cope and Marsh.

If you are looking for a video to entertain children, this is not it. On the other hand, the DVD does have a number of airings of scientific controversies and field operations.

One point I would disagree with. The question of whether dinosaurs resembled birds or reptiles in care of young is addressed by using fossil bone cross sections to determine whether newly hatched dinosaurs had strong enough legs to stand. I strongly suspect that some dinosaurs could stand and some couldn’t, and the same is true of modern birds. Certainly chicks and ducklings are on their legs and finding their own food almost at once, and I suspect at least some dinosaurs may have been the same. I have seen arguments in later DVDs that some pterosaurs (which admittedly are not dinosaurs) were able to fly shortly after hatching.

All in all, this is not a DVD I would consider entertainment, but it could be of interest to a budding paleontologist.

IMAX T-Rex: DVD Review

Back when IMAX theaters were rare and found mostly in museums I went to a 3-D IMAX show – T-Rex – at the Smithsonian Natural History Museum. Even then I found it a peculiar amalgam of three-dimensional animation, paleontology, and not-very-good science fiction. (OK, it’s pretending to be science fiction, but it’s closer to bad fantasy.)

I got the DVD a while back, when I was getting most of the dinosaur videos available.

It’s a 1998 movie, and of course a lot has been learned about T-Rex in the intervening 14 years. Not enough, however, to make me feel like trying to pet one, or think it was capable of gratitude to another species!

Both the animation and the sequences of paleontologists in the field are fascinating, and so is the information about museum displays and Charles Knight. If the producers had stuck to the informational part, and perhaps used the idea of T-Rex as a nurturing mother in a more reasonable way, this could have been an excellent film, though a short one (44 minutes.) However, they insisted on adding a plot which involved something that left the audience guessing whether dreams, hallucinations, or time travel was involved. The supposed resolution, with a paleontologist finding a 20^th century watch, was totally ridiculous. Complex metal objects like watches simply do not fossilize.

Further, neither the big-screen of IMAX nor the 3-D were available in the DVD I have. This was a movie which depended on these effects.

Interestingly, there is considerable current research on the extent to which tyrannosaurs might have lived and hunted in family groups, and it is generally recognized today that birds are fundamentally modern dinosaurs, descended from the same bipedal group to which T-Rex belonged. The DVD, watched with the production date in mind, does give some interesting information on the history of how we think about dinosaurs. Just forget the plot!

p.s: As an update on last week’s post about ice jam floods, there is still a flood warning out for the Salcha River area, and the ice went out at Nenana at 7:39 yesterday evening. This can happen from April 20 to May 20, so breakup this year was early.

The Land of Painted Caves: Review

Jean Auel began her “Children of Earth” series over 30 years ago, with Clan of the Cave Bear. The Valley of Horses, The Mammoth Hunters, The Plains of Passage and The Shelters of Stone followed. Her latest addition, The Land of Painted Caves, continues to follow Ayla and Jondalar, still having difficulty communicating, and this time includes a tour of the cave paintings of France.

All are long books – The Land of Painted Caves is 828 pages in paperback and the others are about the same length. All are well researched. I discovered the series 30 years ago, primarily because of my interest in the Pleistocene and human evolution, and most of this review will be from that perspective.

From a writer’s point of view, the most recent book is full of information dumps, and rather weak on plot. That hasn’t stopped it from being a best seller, but there were times when I had to force myself to pick it up. I did manage to find a number of usable Twitter quotes, which are being posted and their contexts will be explained on February 29.

A good part of the book is description of the cave art of France. Auel does include a map keyed both to what the Zelandonii of her book called the caves and what archeologists call them, but I wanted to see some pictures of the cave art, not just descriptions. I actually searched the web for images from the caves, but found very few even when I knew the name of the cave. Good general references are http://myrencounter.blogspot.com/2011/07/land-of-painted-caves.html and http://www.donsmaps.com/indexauelfans.html, but they have more photos of the locations of the caves than of the actual paintings. White Hollow, identified as Lascaux, does have some images of the art at http://www.huffingtonpost.com/2010/09/12/inside-lascaux-the-versai_n_712645.html.

One possible source, at least for drawings of the cave art, is The Nature of Paleolithic Art, by Dale Guthrie. Dale is an artist himself, and while he suggests that a good deal of the “art” in the caves was equivalent to graffiti found in mens rooms, his first interest in cave art was as guides to reconstructing extinct animals. This is a huge book, with hundreds if not thousands of drawings of Pleistocene art from all over Eurasia, but putting the drawings in this book together with what Ayla saw would be a major project.

Leaving the art, there has long been a controversy in archaeology as to whether modern humans and Neanderthals (what Ayla calls the Clan) ever interbred, or whether such interbreeding was even possible. The argument went back and forth during the time period over which Auel’s books were being written. DNA for a time was used to claim such interbreeding never occurred. Then, less than a year ago, DNA evidence made it quite clear that such interbreeding had in fact happened. The basis of Auel’s books was if anything ahead of the archaeology of the time.

In one point, however, she was clearly wrong, though there was no way she could have known it at the time she started the series..  Jondalar and Ayla are described as being blonde and having blue and gray eyes respectively. Recent gene sequencing has strongly suggested that all blue and gray-eyed people are descended from a single common ancestor who lived between 6,000 and 10,000 years ago, well after the setting of Auel’s books. There is at least some argument that blonde hair may have evolved after the ice ages. Still, I cannot help but wonder if it could be derived from that Neanderthal admixture. If fair coloring is an adaptation to getting vitamin D in a region with little sunlight, such as Europe, the Neanderthals lived in Europe long before the Cro-Magnons arrived.

Bizarre Dinosaurs DVD Review #IAN1

All dinosaurs are bizarre, by mammalian standards. Some, however, are bizarre even to paleontologists, and the title program of this DVD is devoted to them. There is, however, a secondary program, not even mentioned on the cover, which to me was of considerably more interest.

Most of these animals are considered bizarre because they have appendages, preserved in the fossil record, that leave paleontologists wondering just why these animals have that appendage. Take the 33 foot-long Anargasaurus, for instance. Why on earth did this plant-eater have a double row of bony spines down its back? Reconstructions tend to show it with skin forming a double crest supported by those spines, but why? The only answer anyone had come up with is some kind of display crest, like the peacock’s tail.

Display organs are common, especially in today’s birds (which after all are modern dinosaurs) so I suppose it’s as good an explanation as any for such things as the plates of a Stegosaurus (which would have been potato chips to a large carnivore) or for the fanciful neck frills, often richly supplied with blood, of the Ceratopsids. Were horns used to fend off predators, of for fighting off rivals within the species? Or just for display?

In some cases the peculiarities might be associated with feeding. Take the Epidendrosaurus, for instance, a sparrow-sized dinosaur with an incredibly long third finger. Did it use its long finger as the aye-aye in Madagascar today does, to find insects in the bark of trees? Then there’s Nigersaurus, with a broad, flat head with a very wide muzzle resembling a vacuum-cleaner nozzle. Did it stand in one place and hoover up the vegetation?

This DVD is less interesting than most of the National Geographic programs scientifically, but it does show some interesting dinosaurs. If you want information on some of the animals shown, National Geographic has both an interactive site and a magazine article by John Updike.

The secondary program, which was a total surprise, should have been part of the Prehistoric Predators DVD I reviewed earlier. It was concerned with a much more recent animal, one I’d met before in Prehistoric Park—a predatory, flightless bird that could almost hold its own with sabertoothed cats and dire wolves. Certainly it seems to have taken down the same kind of prey.

These terror birds were not what you want to attract to your backyard bird feeder! Imagine an oversized ostrich with the hooked beak of a raptor, that beak (and head) enlarged to the size of a rather large war axe. With ostrich speed and taller than a man, they evolved to be the top predators on the South American continent, for many millions of years an island continent. Then a few million years ago, the isthmus of Panama joined it to North America, ending the isolation in which the terror birds had evolved. Animals crossed the new isthmus both ways. Opossums, armadillos, and porcupines moved north, but a far greater number of placental mammals moved south.

Surprisingly, a few terror birds did move north, as their fossils have been found in Florida. Did they meet with the earliest humans to colonize North America? Or were they simply unable to compete with the mega-predators already here? They did seem to survive for a long time in North America, but the jury is still out on just how long they lasted.

Tomorrow’s the day to look at quotes from Lewis Carroll, but I’ll also have a guest appearance on another blog, Christine’s Words. Stop by!