Feeds:

Archive for December, 2012

Sea lizard

Platecarpus

When I was a boy, I used to catch eastern fence lizards and five-line skinks. I never knew the proper name of the former species.

In West Virginia, they are always called “hell hogs,” which, in my estimation, is far cooler name than “eastern fence lizard.”

The fence lizards are in the suborder Iguania, and they superficially resemble their distant iguana cousins. They even do that head bobbing behavior that iguanas do.

I was always fascinated by iguanas. They were like giant hell hogs, and when I learned that there were iguanas on the Galapagos Islands that actually went into the sea to eat algae, I was utterly amazed.

These were real sea lizards!

What I didn’t know at the time is that the marine iguanas weren’t the first lizards to go into the sea.

The truth is that millions of years ago, there were lizards that were adapted to an entirely marine existence.

As a kid, I didn’t know this.

I thought that dinosaurs actually were large lizards, and all my toy dinosaurs had legs that bowed out like those of a monitor lizard.

One of the sad things about the popular conception of dinosaurs is that we think that name, which means “terrible lizard,” actually means that these animals were lizards.

The truth is that all dinosaurs are more closely related to birds than they are to the little fence lizards of my youth. Some dinosaurs are even closer to birds than that, and now, if we are to classify them systematically, we have to consider birds a subset of dinosaurs. Their technical name is “avian theropod dinosaurs.”

I was somewhat crestfallen when I found this out.

That meant that the only amazing lizards were marine iguanas and my other favorite species, the komodo dragon.

What I didn’t know is that there were actually lizards that were every bit as amazing as any dinosaurs.

And you have to forgive my ignorance here.

I actually didn’t know about the marine lizards known as mosasaurs until about three or four years ago.

When I found out that these truly marine lizards existed, I was elated.

The animal depicted above is Platecarpus. It was a highly derive mosasaur that was once common in the Western Interior Seaway that divided North America into two land masses during the Late Cretaceous.

There is a strong suggestion that its tail bent down and a caudal fin was attached to the bend to make a shark-like tail.

And it was basically a 14-foot shark lizard that lived around 80-85 million years ago. A recent study revealed that it even swam much like a shark, which means it would have been one of the fiercest predators in the seas of its time.

Mosasaurs evolved from an archaic varanoid lizards called aigialosaurids, but this is, of course, hotly contested. Aigialosaurids looked an awful lot like modern monitor lizards, and it has been the recent fashion to count mosasaurs as varanoids. Currently, there is a lot of debate over what’s a varanoid. Some authorities count snakes as a type of highly derived varanoid, and if we count snakes as lizards, then sea snakes are also marine lizards.

But there isn’t a sea snake that is anything like a shark.

Evolution is one of the most amazing facts I’ve come to understand.

When I was a kid, my grandmother would keep little chicks from her laying hens in boxes next to her wood-burning stove. In the early spring, the hens would sometimes get too far ahead of themselves and lay eggs before the spring frosts topped, and very often, the chicks would be exposed to the elements and would die. My grandmother always brought those early spring chicks in, and they would be kept warm by the fire.

I didn’t know that these fragile little fuzzballs were actually more closely related to the Tyrannosaurus than they were to anything else living on the planet at the time.

And I didn’t know that the little lizards I used to hold in my hands and put in mason jars and homemade enclosures once were related to beasts that once rivaled sharks in the ancient seas.

Evolution is one of the most amazing facts you’ll ever understand,.

It will humble you, and it will make you look at the natural world in ways that you never thought possible.

That’s why I want people to understand it.

When I found out exactly what it was about, it was one of the most liberating experiences of my life.

And it really stimulated my imagination.

I know that I won’t look at a common fence lizard without the idea of a mosasaur coming up in the back of my mind.

I will marvel at that little lizard.

Not a mosasaur.

But a cousin of sorts.

Read Full Post »

Pure bliss

078

One a long walk.

Pure bliss.

Read Full Post »

“Living fossil” whale discovered

pygmy right whale

As I have noted in the past, it’s usually a very good idea to be cautiously skeptical of claims coming out of paleontology. Morphological analyses alone– especially those that have been used to determine  phylogeny and taxonomy within the dog family– have often been in error.

But that said, paleontology does occasionally produce something that, well, blows your mind.

If this paper by R. Ewan Fordyce and Felix Marx of the University of Otago in New Zealand is correct, then we have been classifying one baleen whale species has been incorrectly classified.

The pygmy right whale (Caperea marginata) of the Southern Ocean has long been thought to have been a close relative of the bowhead whale (Balaena mysticetus) of the arctic.

However, an extensive study of pygmy right whale morphology and a comparison of their anatomy with extinct whale species suggests that they actually aren’t that closely related to bowheads at all.

It actually has similar features to extinct whales that have been classified into the family Cetotheriidae.

So similar is the pygmy right whale in its morphology to the Cetotheres that authors conclude that it should be included in that family.

And if it is, then this extinct family is resurrected.

Of course, more studies are need to confirm this finding, but if the consensus shows in both morphological and molecular studies, then it will be a great find indeed.

 

 

Read Full Post »

Falcon shares meat with a tazi

Source.

I believe this is a gyrfalcon, but I’m not really sure.

Read Full Post »

500-pound bear killed in West Virginia

giant west virginia bear

Yes. There are bears that big in West Virginia, and this isn’t very far from Parkersburg and the Ohio River.

These bears are almost always eaten.

Read Full Post »

Golden eagle tries to attack baby

This was in Montreal:

Source.

Read Full Post »

“Cat-like bears”

By the middle to late part of the nineteenth century, naturalists began to try to classify animals systematically. They didn’t always get it right, but they generally paid close attention to morphology.

However, they often had a hard time classifying animals that had features that were sort of aberrant. It was easy to see that lion was a cat and that a polar bear was a bear.

But how do you classify creatures that appear to have features of several different species?

Have you ever heard of the term “bear cat”?

It was a term that I always heard as a child, and I thought it referred to a mythical animal.

I later learned that this term actually was nothing more than an archaic term for the binturong, a type of arboreal civet that is native to Southeast Asia.

But I didn’t know that the term actually had some scientific currency beyond it being another name for the binturong.

However, one can see how this term was used in Brehm’s Life of Animals (1896):

Three remarkable animals of southern Asia constitute the second suborder of the Bears, whose members we will call Cat-like Bears (Ailurinae). They are a transitional form between the Large Bears and the Civets, and are distinguished by their somewhat Catlike paws, having slightly retractile claws, and the soles of which are covered with hair.

The first place in this suborder belongs to the Ailuropus (Ailuropus melanoleucus), which was discovered by [Father Amand] David about twenty years ago, and which on the one hand resembles the Large Bears, on the other the Panda. He is of smaller size than the common Brown Bear, measuring about sixty inches from the tip of his snout to the end of his tail. His feet, which have hairy soles, are wide and short,and he does not walk on the entire sole. The snout is short, and the head proportionately broader than that, of any other Beast of Prey. His fur is dense, Bear-like and of a uniform white color, with the exceptions that a ring around the eyes, the ears, the front legs, and a band extending from them up to the shoulder, the hind feet and the tip of the tail, are black.

Next to nothing is known about his life in the wild state. He inhabits the most inaccessible mountainous forests of eastern Tibet.

The representative of the second species of this suborder, the Panda Bear or Red Cat-like bear (Ailurus fulgens),

in a certain way holds the middle position between the Ailuropus and the Binturong. On account of his thick, soft fur, his body appears clumsier than it is; the head is covered with long hair and is very broad and short, and the snout likewise. The long tail is pendent and bushy, having the appearance of being very thick; the ears are small and rounded; the eyes are small; the legs are short; the feet have soles thickly covered with hair, and the walk is semi-plantigrade; the toes are short and the claws are strongly curved. The size of the Panda is about that of a large Tom-cat. The fur is dense and long, of a vivid and lustrous dark red on the upper surface, with a light golden tinge on the back, where the hairs are tipped with yellow; the under surface and the legs are lustrous black, with the exception of a dark chestnut transverse band on the front and sides; the tail is of a Foxy red, indistinctly ringed with narrow bands of a lighter hue.

The Panda is a native of the southeastern parts of the Himalayas, where it is found at an elevation of from six thousand to twelve thousand feet. Little is known about the life in the wild state of this beautiful, dainty creature. It lives in the woods, either in couples or in families, mounts on the trees, and makes its home in their hollows or in clefts of rocks; it spends much time.on the ground in its search for food. It is an almost exclusively vegetable feeder, but is also said occasionally to plunder nests and eat insects.

The last species of the suborder is Southern Asiatic the Binturong (Arctitis binturong), exceeds the Panda in size; his length is from fifty-four to sixty inches, nearly half of this length being taken up by the very long, prehensile tail. The body is stout, the head thick, the snout elongated; the legs short and thick; the feet five-toed, with tolerably strong, somewhat retractile claws; the soles naked. The body is clothed in a thick, rather rough, loose fur. The ears are short, rounded and surmounted by tufts. Thick, white whisker-hairs on both sides of the snout surround the face as with a halo. The color is a dead black, merging into a grayish tinge on the head and into a brownish shade on the limbs.

The Binturong is a native of Borneo, Java, Sumatra, the Malayan Peninsula, Tenasserim, Aracan, Assam and Siam. Its life in the wild state is also very little known. It is nocturnal in habits, leading a principally arboreal life, and is slow in its motions. It is omnivorous, disdaining neither small mammals, birds, fish, worms, and insects, nor fruit and other vegetable food. Living as it does in lonely forests and hidden from view, it is seldom seen; its voice is said to find utterance in a loud howl. Though wild and fierce in disposition, it soon becomes tame when taken young and is as gentle as it is playful(pg. 264).

I’d be remiss if I didn’t include the anatomically incorrect depiction of a binturong walking around like a bear with a long tail.

Brehm's binturong

You’ll note that all of the scientific names given for these animals are still the ones in use today. The “Ailuropus”  is the giant panda, and the only difference between its common name given here and the one used today is that it is now Ailuropoda melanoleuca instead of Ailuropus melanoleuca. The name means “black and white cat foot.”

It is also interest that the term “panda” originally referred to the red panda, not the giant one.  At the time Alfred Brehm was writing this book, we knew next to nothing about giant pandas. We just barely knew they existed, and there were even people who seriously contested their existence.

Because these animals all have morphologies that are relatively similar to each to each other, it would have made sense for nineteenth century naturalists to try to put them all in one family.

But it’s been known for a long time that binturong has nothing to do with either panda.

As noted earlier, the binturong is an arboreal civet, and its prehensile tail makes it the only mammal in the Old World with this feature. Civets are in the family Viverridae. Viverrids are feliform Carnivorans, which means they are more closely related to cats than they are to bears, dogs, or raccoons.

And that means that classifying the binturong with two pandas is quite erroneous.

But that alone would not make Brehm’s proposed family of Ailurinae incorrect.

For most of the twentieth century, the classification of the two species of panda was hotly contested. The two species possess a very similar adaptation for eating bamboo. Their radial esamoid bones have become almost like thumbs, which allows them to grip bamboo for ease of eating. The fact that both animals eat a lot bamboo also suggests a common ancestry. They also have similar scent glands, genitalia, and dentition.

And so it was assumed that the two were related.

But this caused something of a problem.

The red panda is superficially more like a raccoon, and it was long suggested that it belonged in the raccoon family (Procyonidae). The giant panda is more like a bear, so there was a huge debate as to whether the giant panda belonged with the bears or the raccoons.

At one time, it was thought to have too few chromosomes to be a true bear, so it was not classified with them.

It was only in the 1980’s, that it was found that giant panda chromosomes were actually fused bear chromosomes. It has been determined that the giant panda is actually an early offshoot of the bear lineage, and its closest relative is the spectacled bear of South America.

And that means that the giant panda is a bear.

It also destroys Brehm’s Ailurinae.

If giant pandas are bears and binturongs are civets, then there is no family that inlcudes red pandas with these two species.

So what is a red panda?

It’s still a raccoon, right?

Well, no.

It looks a lot like a raccoon, probably because it has a lot of primitive caniform features, which are also found in raccoons.

In 2000, a mitochondrial DNA study found that it was very hard to place the red panda within Carnivora, other than it was clearly located in the clade Musteloidea. a clade that includes skunks and stink badgers (Mephitidae), the weasel family (Mustelidae), and the raccoon family (Procyonidae).  Because its exact position within that clade is not clear, the red panda is classified in its own family called Ailuridae.

Ailuridae is pretty similar to Brehm’s Ailurinae, but it’s not nearly as exotic.

The red panda’s scientific name means “shining cat.” In English, we’ve sometimes called it a “fire fox,” which is where the browser got its name.

But it’s not either of those things.

It’s its own thing.

Systematically classifying organisms has truly been revolutionized with the ability to examine and analyze DNA.

In the late nineteenth century, all they had was morphology.

And morphology led them astray.

Morphology alone fails to take into account the power of convergent and parallel evolution, and that’s why we molecular techniques are superior at resolving phylogenetic questions.

It’s also why I take everything I read about paleontology with a grain of salt.

In really old organisms, all we have is morphology.

And if it’s led us astray with animals we can actually examine alive, imagine what it’s done with things like non-avian dinosaurs.

 

 

 

Read Full Post »

« Newer Posts - Older Posts »

Follow