Thanks for repairing my link. It worked when I posted it, but for some reason msn.com has been unreliable in keeping it up, whereas almost any other service still has it if you just search "oreodont new mexico."

...and I was so proud of putting it up as a short-cut, instead of my usual "http etc."!

I read Oreo-dont as "oreo-tooth." I figure "oreo" probably had a different scientific meaning than the more common three-layer sweetie, but what the heck. I've based puns on a lot less than that!

Originally posted by Steviepinhead

Thanks for repairing my link. It worked when I posted it, but for some reason msn.com has been unreliable in keeping it up, whereas almost any other service still has it if you just search "oreodont new mexico."

...and I was so proud of putting it up as a short-cut, instead of my usual "http etc."!

I read Oreo-dont as "oreo-tooth." I figure "oreo" probably had a different scientific meaning than the more common three-layer sweetie, but what the heck. I've based puns on a lot less than that!

It was probably in an attempt to avoid bad puns that the name Oreodont was officially changed to Merycoidodon.

Originally posted by rogue06

It was probably in an attempt to avoid bad puns that the name Oreodont was officially changed to Merycoidodon.

Time to relabel my collection!

I have a pun for Merycoidodon, too, but it's a little too cheesy for this forum.

Though maybe some of you will be able to work it out for yourselves if I break the nomenclature down a little: Mery - coido - don!

(Just be sure to practice safe, er, "coido" there, don-boy, however much "merry" you make!)

Sam Head, a PhD research student from the University of Portsmouth, has discovered a new species of extinct flying grasshopper from around 115 mya while examining fossils from two German museums that had been improperly labeled “stick insects.” After comparing the fossil with other species of grasshoppers, Head quickly realized that it was actually an ancient ancestor of modern grasshoppers belonging to a family called Proscopiidae that hadn’t been noticed before because of the mislabeling. This discovery extends the geological range of the Proscopiidae back nearly 120 million years and allows us a look into the otherwise unknown evolutionary history of the family.

He named the newly-discovered insect Eoproscopia martilli, after his university mentor Dr Dave Martill a professor at the School of Earth and Environmental Sciences at the University of Portsmouth. It was about 5cm long with a short head and well-developed wings and belonged to a family which still survives, whose familiar names include jumping sticks, stick grasshoppers and horse-head grasshoppers. Today Eoproscopia’s descendants have elongated heads and have either lost their wings or seen them evolve into mere stumps or tiny winglets. Proscopiids are “stick mimics” and it is plausible that becoming a better stick required a significant reduction of the wings. Once the wings had become too small for flight, they could have disappeared through natural selection.

Head has pointed out that the discovery has raised at least as many new questions as it is likely to answer. For instance, during the early part of the Cretaceous South America and Africa were still connected and this grasshopper would have little difficulty moving between the two continents, yet no proscopiids live in Africa today though they are common in South America.

Read more here:

Ancient species of flying grasshopper found

Fossil find brings new discovery

sweetness.

Turtles are ancient creatures, with the first ones appearing over 200mya during the Triassic, evolving before either snakes or crocodiles and preceding dinosaurs. Yet establishing their exact ancestry has been difficult and somewhat controversial. Modern turtles have been separated into two primary groups – the Cryptodira and the Pleurodira – based on where on its skull the muscles that close the lower jaw are fastened. Since the 1970s the consensus among the experts has been that almost all the extinct fossil turtles fit into either of these two groups, which means that the common ancestor of these turtles originated very early in turtle’s history. This view has been challenged by research by Walter Joyce, a paleontologist from Yale, who is calling for a overhaul of this classification. After studying the anatomical features of fossil turtles, Joyce declared that many of them don’t belong to either of the modern groups and that modern turtles evolved considerably later than was formerly believed, approximately 150 mya.

The recent discovery of a 35cm (about a foot and a half) long fossil turtle in the Patagonian region of Argentina dated between 146 and 160 myo (Middle to Late Jurassic) appears to support Joyce’s new interpretation of the fossil record for turtles. Called Condorchelys antique, it has been analyzed and described by Juliana Sterli, a PhD student at the Museo de Historia Natural de San Rafael in Mendoza, Argentina. “Condorchelys doesn’t belong to the Cryptodira or Pleurodira and fits Joyce’s hypothesis that the modern groups are at least 60 million years younger than previously thought,” Sterli noted.

These conclusions aren’t without detractors however. Eugene Gaffney, the paleontologist from the American Museum of Natural History (AMNH) in New York City who made the first detailed study of turtle fossils over 30 years ago that divided all fossil turtles into either Cryptodira or Pleurodira, disagrees. While acknowledging the importance of the discovery of Condorchelys (fossil turtles from this time are extremely rare), he thinks that it is probably a primitive Cryptodira and hence doesn’t support Joyce’s reinterpretation of the evolution of turtles.

Further reading:

Living Turtles, More Modern Than Previously Thought – By 60 million years

Modern Turtles Much Younger Than Thought?

New Primative Jurassic Turtle, Condorchelys antique I hesitated in adding this one due to the accompanying photo.

The fossilized remains of a small plant-eating lizard have been discovered in 130 myo Early Cretaceous period deposits of the ‘Kaseki-Kabe’ or ‘fossil-bluff’ in Kuwajima, Hakusan City, Ishikawa Prefecture, Japan, and appear to be the oldest remains of an herbivore lizard yet found. Herbivore lizards are rare with the vast majority instead being carnivorous. Previously, the oldest herbivore lizard species known was from the western United States and was only approximately 99.6 myo. It has been named Kuwajimalla kagaensis, after where it was unearthed, the Kuwajima Kaseki Kabe (a bluff designated as a national treasure for the many fossil vertebrates discovered there). The Latin part of the name means “little maiden” at Kuwajima in Kaga (the name for the Ishikawa Prefecture back in feudal times). Kuwajimalla is believed to have been about 25 to 30cm (about a foot) long. Comparisons with both fossil lizards and those around today indicate that Kuwajimalla appears to be a basal macrocephalosaurine (a group of large herbivores well represented in the Late Cretaceous of Mongolia) or perhaps a basal boreoteiioid with specialized dentition. More material is needed before this can be determined with any confidence.

Eleven pieces were found including parts of the lizard's upper and lower jaws, its skull and several teeth. It is the teeth, somewhat similar to those of modern Iguanas, that indicate that Kuwajimalla was an herbivore, specifically a Folivore (one that eats leaves). These leaf-shaped teeth are only 2mm long and slightly less than half a millimeter wide, with jagged edges making them suitable for chewing on plants, whereas the teeth of meat-eating lizards are sharp like a knife.

The lizard is described by Makoto Manabe, a senior curator at the National Museum of Nature and Science, and Susan Evans, a professor at University College London in the most recent edition of “Palaeontology” magazine, published in Britain (which I don’t have access to ).

Further reading:

Fossils called world's oldest plant-eating lizard

AN EARLY HERBIVOROUS LIZARD FROM THE LOWER CRETACEOUS OF JAPAN Abstract

VESTIGIAL EGG-YOLK GENES IN MAMMALS

From PZ Myers' Pharyngula blog.

(I hope rogue doesn't mind my inserting the occasional linky here!)

Ursus maritimus got to this story first, and has put up a separate thread about it, but I thought I'd cross-link it here.

Here's a prediction (or "retrodiction," or whatever) for you: if placental mammals and egg-laying birds and reptiles shared a common ancestor, and if yolk was the earlier method of providing nutrition to developing young, then we ought to find "decayed," or "eroded"--no longer functional--genes for making egg yolk in mammals, right?

(Mammal embryos--and, yes, human ones--do exhibit a yolk sac, but there's no yolk contained therein...)

And it's much harder to explain why we would "share" these vestigial genes at all if, as creationists argue, the mammal "kinds" were created separately from the reptile and bird "kinds" (and particularly if the human species was an even more special and unique creation).

Of course, creationists can always gin up an all-purposes non-explanation, like "the creator works in mysterious ways" or "the creator placed versions of pret' near every gene in pret' near every critter."

Except--another prediction--a cladistic chart of yolk genes extended further back in evolutionary time--when and if one is constructed--would independently trace out the same common vertebrate and bilaterian phylogenies as do the fossil and overall genetic "trees," and at some point would show a common origin for the yolk-gene family among egg-laying bilaterians or metazoans generally, and almost certainly those earliest yolk genes will be found to be a modification of some other set of genes, "used" for some other purpose, by even earlier animals.

Distant relatives of the yolk genes still produce fatty substances that circulate in our blood, and contribute to our arthersclerotic tendencies in our present more-sedentary circumstances.

I particularly like PZ's imagery for the process of determining the time period over which gene families have been diverging (and, in this case, in mammals, decaying). "Vitellogenin" is the egg-yolk protein:

When non-functional genes, called pseudogenes, like this are found, one thing one can do is estimate the time of loss of function from the amount of decay. Natural selection is a force that maintains genes, and in its absence, they tend to slowly fall apart as they accumulate mutations. Browsing through the genome is like strolling through a run-down neighborhood. Houses that are still occupied will be maintained and kept up. Houses that have been recently abandoned might have an overgrown lawn and broken windows. Houses that have been neglected longer still might show signs of fire damage, or structural collapse, or might have been demolished right down to their foundations. By measuring the divergence of mammalian pseudogenes for vitellogenin from bird vitellogenin genes, for instance, we can estimate the time of loss.

Originally posted by Steviepinhead

VESTIGIAL EGG-YOLK GENES IN MAMMALS

From PZ Myers' Pharyngula blog.

(I hope rogue doesn't mind my inserting the occasional linky here!)

Not in the least! The more the merrier.

Ursus maritimus got to this story first, and has put up a separate thread about it, but I thought I'd cross-link it here.

Here's a prediction (or "retrodiction," or whatever) for you: if placental mammals and egg-laying birds and reptiles shared a common ancestor, and if yolk was the earlier method of providing nutrition to developing young, then we ought to find "decayed," or "eroded"--no longer functional--genes for making egg yolk in mammals, right?

(Mammal embryos--and, yes, human ones--do exhibit a yolk sac, but there's no yolk contained therein...)

And it's much harder to explain why we would "share" these vestigial genes at all if, as creationists argue, the mammal "kinds" were created separately from the reptile and bird "kinds" (and particularly if the human species was an even more special and unique creation).

Of course, creationists can always gin up an all-purposes non-explanation, like "the creator works in mysterious ways" or "the creator placed versions of pret' near every gene in pret' near every critter."

Except--another prediction--a cladistic chart of yolk genes extended further back in evolutionary time--when and if one is constructed--would independently trace out the same common vertebrate and bilaterian phylogenies as do the fossil and overall genetic "trees," and at some point would show a common origin for the yolk-gene family among egg-laying bilaterians or metazoans generally, and almost certainly those earliest yolk genes will be found to be a modification of some other set of genes, "used" for some other purpose, by even earlier animals.

Distant relatives of the yolk genes still produce fatty substances that circulate in our blood, and contribute to our arthersclerotic tendencies in our present more-sedentary circumstances.

I particularly like PZ's imagery for the process of determining the time period over which gene families have been diverging (and, in this case, in mammals, decaying). "Vitellogenin" is the egg-yolk protein:

Two fossil discoveries of ancient ‘waskly wabbits’ have recently been located.

The first one is the oldest (55 myo) as well as the most complete fossilized skeleton of an ancient rabbit yet dug up. Named Gomphos elkema, and found in the Gobi Desert in Mongolia, it is approximately 20 million years older than the previous record holder and possessed a hindlimb that was much longer than the forelimb indicating that it probably hopped around much like its descendants do today. But while it may have had a classic “rabbit’s foot” it did have several features that mark it as being very different than today’s rabbits and hares. These include a large tail and teeth that more closely resemble those of a squirrel than of a rabbit as well as a more primitive jaw. Overall, this blend of features from both modern rodents and lagomorphs (the family which includes rabbits, hares and pikas) supports the formerly contentious, though now generally accepted proposal that these two groups are closely related.

Prior to the discovery there has been a fierce debate raging among paleontologists about when placental mammals first evolved. One camp argued that they existed well before the KT extinction event that killed off the dinosaurs 65 mya whereas the other side insisted that that they didn’t come on the scene until much later, either just before or even slightly after this event. Inadequate fossil evidence has kept either side from amassing definitive evidence for their case, but with the discovery of Gomphos the evidence has tipped strongly in favor of the later hypothesis.

"This extremely well-preserved fossil is providing a new contribution to the question of the divergence in the early evolution of placental mammals and lagomorphs, in particular," said Dr. Meng, Associate Curator of the American Museum Of Natural History’s Division Paleontology. "Our results basically say the divergence of the mammal group that includes lagomorphs occurred after the K-T boundary, 65 million years ago. This supports the conventional view that the timing of the divergence is not way back into the Cretaceous but is closer to the K-T boundary."

Still, gene differences detected by molecular biologists indicate that lagomorphs are closely related to a primitive and extinct group of Central Asian Cretaceous age mammals known as "zalambdalestids,” which were around some 80 million years ago, so it looks as if the controversy will continue.

The second find occurred while anatomy professor Kenneth Rose was displaying some fossilized ankle bones dating from 53 mya that were found in the Vastan lignite mine located north-east of Mumbai in Gujarat, west-central India. While using them as part of his lecture Rose noticed that they looked somewhat familiar and after some checking found that they strongly resemble those found in modern lagomorphs, but slightly less than a quarter of their size. Apparently he hadn’t made the connection sooner because rabbits weren’t thought to have inhabited that part of the world at that time.

Further analysis would reveal that the bones were definitely Lagomorph and while they resembled pikas in some primitive features, they are more similar to rabbits in specialized bone features. What this suggests is that approximately 35 mya, during the Early Eocene, rabbits and hares had begun to diverge from pikas. Furthermore, the dates and locations of the find indicate that some of their early evolution occurred while India was beginning to collide with Asia. But as Rose has noted, "what we really would like are some teeth that tell how different these animals really were."

Further Reading:


Oldest fossil 'rabbit' unearthed

EARLIEST RABBIT FOSSIL FOUND, SUGGESTS MODERN MAMMAL GROUP EMERGED AS DINOSAURS FACED EXTINCTION

and

Good Luck Indeed: 53 Million-year-old Rabbit's Foot Bones Found

Fossil finds are rabbit forebears

Being the pinhead that I am, I was a mite confused on how the first find (of the early rodent-lagomorph) constrained the date of divergence of the placental mammals/eutherians (from, presumably, the metatherians/marsupials).

Since the lagomorph-rodent clade (assuming there is one) would be a subclade of all placental mammals, it seems sensible to me to suppose that a 55 myo fossil representing a less-derived member of that clade probably possessed a placenta.

But that would seem to me to qualify as evidence for a date no later than which placental mammals certainly existed, not necessarily evidence of a date no earlier than which placental mammals could not have existed.

If you see what I mean.

Similarly, in yesterday's discussion (scroll up to post #10 on the page) of the "fossil" egg-yolk genes in mammals, the authors placed the divergence between the mammalian superorders which gave rise to, respectively, dogs and humans at ~90-100 MYA. Again, I would assume that since both dogs and humans are placental mammals, their common ancestor must have been one as well.

If true, this would easily push the date of the divergence of placental mammals from other mammals well back before the K-T boundary (and in fact the egg-yolk paper suggests that the eutherians diverged from the metatherians as far back as roughly 180 MYA).

Now, just because the eutherians may have diverged from the metatherians 180 MYA doesn't mean that the common ancestor of all marsupials and placentals had a placenta. Au contraire! It stands to reason that this common ancestor of all "therians" did not have a placenta. The placenta presumably evolved later in some eutherian common ancestor of all placental mammals, after the eutherian-metatherian divergence and before the proto-wolf/proto-human divergence.

Based on the foregoing, I continued to wonder how the 55 MYO lagomorph paper could be commenting on the date of the evolution of the placenta--which presumably came before the divergence of any of the modern placental mammal groups--or if instead, it meant to be commenting on a somewhat different question:

the question of the divergence in the early evolution of placental mammals and lagomorphs, in particular

(My bold and italics.)
While this is somewhat ambiguous (as between the divergence OF the placental mammals vs. a divergence of early rodent-lagamorphs FROM the rest of the early placental mammals), Dr. Meng of the AMNH goes on to say:

Our results basically say the divergence of the mammal group that includes lagomorphs occurred after the K-T boundary, 65 million years ago. This supports the conventional view that the timing of the divergence is not way back into the Cretaceous but is closer to the K-T boundary.

Though the meaning of the second use of "the divergence" remains ambiguous, it seems to me, then, that while this find furnishes evidence that the "mammal group that includes lagomorphs occurred after the K-T boundary," it does not necessarily furnish evidence that the divergence of placental mammals from their common (placenta-bearing) ancestor could not have occurred significantly earlier, even "well back into the Cretaceous."

Still, as this longer quote (extracted from rogue's second link above) indicates, the researchers do seem to be suggesting that their find ALSO comments to some extent on the larger question of the origin of placentals:

Some paleontologists claim that ancient relatives of modern groups such as rabbits can be found in the fossil record tens of millions of years before the K-T boundary. An extinct Central Asian group of mammals called zalambdalestids are known to be more than 85 million years old, and they shared a close evolutionary relationship with modern rabbits, a hypothesis suggested by some paleontologists. Because G. elkema preserves so much information about the anatomy of ancient rabbits and their kin, the Museum team and their colleagues included it in a new analysis of the family relationships among mammals and found strong evidence against the point of view that zalambdalestids are evidence of modern mammals in the Cretaceous Period (spanning 145 to 65 million years ago). Instead, the team found that modern rabbits are more closely related to a group that includes rodents, primates, tree shrews, ungulates, and other modern placental mammals than to any mammal known before the K-T boundary.

This extremely well-preserved fossil is providing a new contribution to the question of the divergence in the early evolution of placental mammals and lagomorphs, in particular," said Dr. Meng. "Our results basically say the divergence of the mammal group that includes lagomorphs occurred after the K-T boundary, 65 million years ago. This supports the conventional view that the timing of the divergence is not way back into the Cretaceous but is closer to the K-T boundary." Such a conclusion is at odds with estimates by some molecular biologists based on gene differences showing that lagomorphs and other placental mammals may have diverged at least 80 million years ago, well into the Cretaceous and long before the K-T extinction event.

So, in addition to showing that the placental group including lagomorphs had become identifiable no later than 55 million years ago, the researchers claim to have ruled out ("found strong evidence against the point of view that") lagomorphs are closely related to the 85 myo (and pre-KT) zalambdalestids.

This arguably knocks at least one prop out from under the placentals-before-KT argument (though, again, saying that rabbits-ain't-pre-KT-zalambies is NOT quite the same as saying that placentals-could-NOT-have-diverged-pre-KT).

And we still have the alleged divergence of the human-doggie superorders, which our other paper places at an even earlier date than zalambies...

Which leads me back to the basis for that date in the yolk paper, which leads to fn. 23:

Murphy W, Pevzner P, O’Brien S (2004) Mammalian phylogenomics comes of age. Trends Genet 12: 631–639.

So that would appear to be a genetic date, and not a fossil date.

I'll wrap up by suggesting that the common ancestor of modern placentals could still have lived earlier than 100 MYA, but no later than 55 MYA.

(Well before Noah's Flood, at any rate!)

Originally posted by Steviepinhead

Being the pinhead that I am, I was a mite confused on how the first find (of the early rodent-lagomorph) constrained the date of divergence of the placental mammals/eutherians (from, presumably, the metatherians/marsupials).

Since the lagomorph-rodent clade (assuming there is one) would be a subclade of all placental mammals, it seems sensible to me to suppose that a 55 myo fossil representing a less-derived member of that clade probably possessed a placenta.

But that would seem to me to qualify as evidence for a date no later than which placental mammals certainly existed, not necessarily evidence of a date no earlier than which placental mammals could not have existed.

If you see what I mean.

Similarly, in yesterday's discussion (scroll up to post #10 on the page) of the "fossil" egg-yolk genes in mammals, the authors placed the divergence between the mammalian superorders which gave rise to, respectively, dogs and humans at ~90-100 MYA. Again, I would assume that since both dogs and humans are placental mammals, their common ancestor must have been one as well.

If true, this would easily push the date of the divergence of placental mammals from other mammals well back before the K-T boundary (and in fact the egg-yolk paper suggests that the eutherians diverged from the metatherians as far back as roughly 180 MYA).

Now, just because the eutherians may have diverged from the metatherians 180 MYA doesn't mean that the common ancestor of all marsupials and placentals had a placenta. Au contraire! It stands to reason that this common ancestor of all "therians" did not have a placenta. The placenta presumably evolved later in some eutherian common ancestor of all placental mammals, after the eutherian-metatherian divergence and before the proto-wolf/proto-human divergence.

Based on the foregoing, I continued to wonder how the 55 MYO lagomorph paper could be commenting on the date of the evolution of the placenta--which presumably came before the divergence of any of the modern placental mammal groups--or if instead, it meant to be commenting on a somewhat different question:

(My bold and italics.)
While this is somewhat ambiguous (as between the divergence OF the placental mammals vs. a divergence of early rodent-lagamorphs FROM the rest of the early placental mammals), Dr. Meng of the AMNH goes on to say:

Though the meaning of the second use of "the divergence" remains ambiguous, it seems to me, then, that while this find furnishes evidence that the "mammal group that includes lagomorphs occurred after the K-T boundary," it does not necessarily furnish evidence that the divergence of placental mammals from their common (placenta-bearing) ancestor could not have occurred significantly earlier, even "well back into the Cretaceous."

Still, as this longer quote (extracted from rogue's second link above) indicates, the researchers do seem to be suggesting that their find ALSO comments to some extent on the larger question of the origin of placentals:

So, in addition to showing that the placental group including lagomorphs had become identifiable no later than 55 million years ago, the researchers claim to have ruled out ("found strong evidence against the point of view that") lagomorphs are closely related to the 85 myo (and pre-KT) zalambdalestids.

This arguably knocks at least one prop out from under the placentals-before-KT argument (though, again, saying that rabbits-ain't-pre-KT-zalambies is NOT quite the same as saying that placentals-could-NOT-have-diverged-pre-KT).

And we still have the alleged divergence of the human-doggie superorders, which our other paper places at an even earlier date than zalambies...

Which leads me back to the basis for that date in the yolk paper, which leads to fn. 23:

So that would appear to be a genetic date, and not a fossil date.

I'll wrap up by suggesting that the common ancestor of modern placentals could still have lived earlier than 100 MYA, but no later than 55 MYA.

(Well before Noah's Flood, at any rate!)

Excellent analysis! I really don’t have an answer to your question here. In fact I was thinking some of the same things, but was unable to express it as you so eloquently did here, so I settled for pointing out that the finding is still controversial in light of the genetic evidence.

T'anks, rougie! But there's something to be said for concision (the best example of which is Sari)...!

It'd be interesting to perform some sort of survey--or to look for somebody else's performance, probably much easier!--of the most current fossil (i.e., lithic not genetic) evidence for early placental mammal divergences and see what kind of dates could be blackboarded up. I have a suspicion that as the genetic dates become increasingly refined and more discoveries like the early rodent-lagomorph are made, that we'll begin to see some sort of convergence-consensus forming...

I'm wondering if we have an analog of (what I sometimes think about) the pre-Cambrian here: lots of fairly-similar looking "early" mammals in the Cretaceous, where it's difficult for us to tell how far along the road to the divergent birthing/care-of-infant strategies they are--

(comparable, perhaps, to lots of very "similar" small, soft-bodied wormy body plans in the pre-Cambrian, for a controversially longer or shorter time, but evidently milling around and leaving burrows and other traces)

--and then, once the K-T transition had taken place (asteroid struck, dikes opened and lava started tripping and trapping out, or whatever other factors may have prompted that transition), and lots of (from Teh Mammalacious perspective) novel niches had become available, enough differentiation occurred quickly enough that the various orders and superorders of "modern" placentals become apparent, confirming that placentas were for sure in existence--

(comparable to the "explosion" and differentiation of larger, hard-part-incorporating body-plans into the diversity of niches made available by whatever factors triggered the Cambrian transition)

--which raises the (to me) further fascinating question of what "we" (or "our" hypothetical far-future successors, or alien xenobiologists, or whoever) might make of the different mammalian "body-plans" in a few hundred million years.

Today, despite some at-times-"confusing" exceptions like the cetaceans, most mammals still exhibit a rather obvious group of similarities--fur, lactation, the tetrapodal arrangement of limbs, etc., some 65 million years (give or take) after the mammalian "explosion."

But what further and much more extreme diversifcations might the bat clade or the cetacean clade or the primate clade (though it's one of the most endangered) or the carnivore clade or the lagomorph clade exhibit in the relatively far future ...

...given another several hundred years of erosion and uplift and plate tectonics and climate cycles and ice ages and bolide impacts and LIPs (Large Igneous Provinces, like the Deccan, Siberian, or Columbia Basin "traps")--not to mention "terraforming" modifications and extinctions inflicted by us or our successors--how many fossils from the mammalian "explosion" are likely to remain to reveal the now-obvious connections between what--in that far future--might easily be seen as highly-distinct "phyla"?

Got another plesiosaur fossil find, this time from northern Alberta Canada. Originally unearthed back in 1994 at a Syncrude Canada Ltd. Base Mine (an oilsands mine), about 35 km north of Fort McMurray near the Athabasca River, the discovery represents one of the oldest, most complete and best preserved North American plesiosaurs yet found. The fossilized skeleton wasn’t crushed and was in exactly the same position it was when it died. It was uncovered some 60 meters below the surface and is missing only its left forelimb and shoulder blade and is thought to have lived around 112 mya (Cretaceous). The 2.6 meter long creature was named Nichollsia borealis after the late Elizabeth (Betsy) Nicholls, a well-respected paleontologist and a former curator at the Royal Tyrrell Museum in Drumheller, who died of breast cancer in 2004.

The reason the discovery is important, aside from being an incredible specimen to study (allowing researchers a chance to study its three-dimensional skull CT-scanned for one thing), is that Nichollsia represents a new genus, helps to fill a 40 million year gap in the fossil record of plesiosaurs, and significantly increases our knowledge about the ancient seaway that once split North America in two.

“This individual was a pioneer in the marine waters that would eventually become the Cretaceous Western Interior Seaway, which ran the length of North America during much of the Cretaceous and was home to one of the world’s most diverse communities of marine reptiles,” Patrick Druckenmiller, a former grad student at the University of Calgary and now curator of earth sciences at the University of Alaska Museum said. “It represents the oldest known forerunner of this amazing period in North American prehistory.” She and University of Calgary biological sciences professor Anthony Russell named the plesiosaur as well as described it in a paper just published by Palaeontographica Abteilung, a German research journal. "This fills in a lot of information about a poorly understood period in the history of these animals," remarked Dr. Russell.

Further Reading:

Oldest Cretaceous Period Dinosaur Discovered Represents New Genus Of Prehistoric Aquatic Predator

Ancient sea reptile from Alberta oilsands yields research bounty

Article in Edmonton Sun

Originally posted by rogue06

Got another plesiosaur fossil find, this time from northern Alberta Canada. Originally unearthed back in 1994 at a Syncrude Canada Ltd. Base Mine (an oilsands mine), about 35 km north of Fort McMurray near the Athabasca River, the discovery represents one of the oldest, most complete and best preserved North American plesiosaurs yet found. The fossilized skeleton wasn’t crushed and was in exactly the same position it was when it died. It was uncovered some 60 meters below the surface and is missing only its left forelimb and shoulder blade and is thought to have lived around 112 mya (Cretaceous). The 2.6 meter long creature was named Nichollsia borealis after the late Elizabeth (Betsy) Nicholls, a well-respected paleontologist and a former curator at the Royal Tyrrell Museum in Drumheller, who died of breast cancer in 2004.

The reason the discovery is important, aside from being an incredible specimen to study (allowing researchers a chance to study its three-dimensional skull CT-scanned for one thing), is that Nichollsia represents a new genus, helps to fill a 40 million year gap in the fossil record of plesiosaurs, and significantly increases our knowledge about the ancient seaway that once split North America in two.

“This individual was a pioneer in the marine waters that would eventually become the Cretaceous Western Interior Seaway, which ran the length of North America during much of the Cretaceous and was home to one of the world’s most diverse communities of marine reptiles,” Patrick Druckenmiller, a former grad student at the University of Calgary and now curator of earth sciences at the University of Alaska Museum said. “It represents the oldest known forerunner of this amazing period in North American prehistory.” She and University of Calgary biological sciences professor Anthony Russell named the plesiosaur as well as described it in a paper just published by Palaeontographica Abteilung, a German research journal. "This fills in a lot of information about a poorly understood period in the history of these animals," remarked Dr. Russell.

Further Reading:

Oldest Cretaceous Period Dinosaur Discovered Represents New Genus Of Prehistoric Aquatic Predator

Ancient sea reptile from Alberta oilsands yields research bounty

Article in Edmonton Sun

About 10 years ago I was fortunate enough to spend 2 weeks in Alberta and BC. Drove to Drumheller and spent the whole day going through the Royal Tyrrell Museum. The quantity and quality of the fossil specimens they have there is mind boggling. Highlight of the trip was going to Yoho National Park, and taking a docent-led hike to the actual Burgess shale site and seeing some Cambrian fossils in situ.

I have to believe most YECs would drop their 6000 year old Earth nonsense in a heartbeat if they could actually see some of this magnificent natural history first hand.

- T