Xiphactinus: The Inception Fossil

If you were to travel back 100 million years from where I live in Colorado, the face of a very, very different planet would emerge.  I suppose emerge isn't necessarily the best word in this context: submerged is more of an adequate description!  You see, unlike the mountains you would see in Colorado today, Late Cretaceous Colorado was even flatter than present-day Kansas....and a whole lot closer to sea level!  Between about 100 and 70 million years ago (MYA), an enormous seaway stretched northwards from the Gulf of Mexico, and southwards from the Arctic.  Within these waters, hundreds, perhaps thousands of animals flourished, many of which we have nothing like today.  Massive sea turtles like Archelon slowly swam through the waters, while the long-necked plesiosaurs cruised around, snapping up fish before they even knew they were there.  While sharks and mosasaurs were probably the most impressive denizens of the seaway, these massive carnivores fed on fish as well.  And the subject of today's post is one of those fish: a 17-foot long beastie called Xiphactinus.

Due to the numerous pictures uploaded to Pinterest by the Best Western Denver Southwest hotel (read more about it HERE), I'm going to be using a lot of pictures from this site!  Make sure you check it out by clicking HERE!  Unless otherwise noted, photo credit for all of the pictures in this post goes to that Pinterest page!

Why did I call Xiphactinus (pronounced zye-FACT-un-us) "The Inception Fossil?"  Well, that's a description that I came up with (don't ever let anyone tell you otherwise!) that has to do with one of the most interesting things about Xiphactinus: numerous specimens of the fish have been found with the remains of other fish in its stomach!  Just as the premise behind Inception is "a dream within a dream," so too are specimens of Xiphactinus sometimes "fish within a fish!"  The specimen below is a thirteen foot Xiphactinus that died with a fish known as Gillicus arcuatus in its stomach!

Unlike sharks, Xiphactinus would have been unable to bite off chunks of flesh from its prey, and instead would have had to swallow its prey whole, which is what makes the Inception Fossils so spectacular!  Some paleontologists propose that this lack of chewing may have been what killed some of these Xiphactinus specimens, and that they actually choked to death on their last meal!  I suppose it's possible, but I don't actually know enough about these specimens to be a very good authority on them!

The next three pictures below are pictures that I took of a specimen that I saw a week or so ago.  Long story short, my friends Isabel and Sam Lippincott and I had gone to a presentation given by paleontologist Dr. Ian Miller about the Snowmastodon Project a few months back, and he was impressed with Sam's paleo drawings when we showed him after the lecture.  He invited us to come on down to the Denver Museum of Nature and Science so that he could show us around behind the scenes, which he very kindly did a few weeks ago!  These are pictures I took of the 80 MY old Mancos Shale specimen of Xiphactinus, which was discovered in 1966 by some kids who had been hunting with their dad near Snowmass in Colorado.  They had stumbled across the rib cage of the animal, and had notified the Denver Museum.  The next summer, the museum excavated the remarkably complete, 13-foot specimen, taking it back to the museum, where it has been stored to this day!

Here are some more cool pictures from the Pinterest page!  This is a diorama of paleontologist Charles Sternberg caught in the act of discovering one of his "Inception fossils!"

And here are another pair of reconstructions of Xiphactinus!

Make sure to check out the Pinterest page of the Best Western Denver Southwest by clicking HERE!

Animal of the Day: Coelophysis

Today's Animal of the Day is Coelophysis!  The picture of the cast you see off to the left (taken by me at the Denver Gem and Mineral Show a few months back) is from the AMNH (American Museum of Natural History) in New York.  I actually know a little bit more about this particular specimen of Coelophysis than I believe was labeled there, as I remembered seeing this specimen in my Dinosaur Atlas book from DK Publishers.  One of around 500 or so individual Coelophysis specimens discovered at a place called Ghost Ranch in New Mexico, this particular specimen was once thought to reveal something interesting about the species: Coelophysis was once thought to probably be a cannibal, as the remains of a baby Coelophysis were found in the area of the stomach!

Dinosaur cannibalism is not unheard of, and almost certainly occurred in the Late Cretaceous Abelisaur Majungasaurus from Madagascar.  However, this was disproven in 2002 by Rob Gay, when he showed that the baby Coelophysis were either crushed by the smaller ones, or that they weren't even baby Coelophysis!  Instead, many of them were found to be other, small reptiles, such as the archosaur Hesperosuchus, a member of the same group as the crocodilians, dinosaurs, and pterosaurs, amongst others.  So for now, it looks like Coelophysis was probably not a cannibal, but future discoveries may force us to change our minds once again!

Another picture of Coelophysis that I took, at the DMNS

Coelophysis is one of the oldest known dinosaurs, inhabiting North America around 220 million years ago (MYA), during the Late Triassic Period.  The site at Ghost Ranch is interesting, because there are just so many different specimens all clumped together.  Some paleontologists have suggested that a flash flood drowned a huge herd of these animals, or perhaps that they died while trying to cross a river.  We might never know what, exactly, killed these dinosaurs, or why so many of them died in such close proximity.  

Cal Orck'o: Not A Place for the Acrophobic

In 1994, Klaus Schütt discovered an enormous slab of dinosaur tracks.  You're probably thinking enormous like Jabba the Hutt enormous or my cat enormous.  (She's a big kitty).  But no, I mean ENORMOUS enormous.  And by ENORMOUS enormous, I mean a mile wide and 500 feet tall.  Yeah, that big.  Another thing about Cal Orck'o: its on a 70 degree incline.

Real fast, let me include a brief disclaimer: I have looked at probably 25 different books and websites that mention this place, and half of them spell it "Cal Orco," and the other half spell it "Cal Orko," while a few even spell it "Cal Orcko."  The UNESCO website calls it "Cal Orck'o," so that's the one that I went with on the blog.  So yeah, I really don't know which way is which, but nevertheless, this place is quite an interesting fossil site!

It wasn't until 1998 that Christian Meyer, a Swiss paleontologist, lead a team of scientists to investigate the site, which is near a concrete factory in Sucre, Bolivia.  They found that the enormous trackway is from the Late Cretaceous Period, dated at around 68 million years ago (MYA).  They learned that, at the time that the rocks and footprints were formed, the area was a lakeside where animals from all over would come to drink.  They also determined that Cal Orck'o was the "largest site of dinosaur tracks found so far," possessing the largest number of dinosaur footprints of anywhere in the world.

Cal Orck'o has over 5,000 dinosaur tracks made by at least six identified dinosaurs in around 250 trackways, some of which extend for hundreds of feet in a single direction.

Due to the extremely steep face of the fossil site, erosion is a constant threat to the dinosaur footprints.  The Bolivian government combats this by spending a whopping $30 million every year.  Despite this, a large chunk broke off in February of 2010, destroying around 300 footprints.   

Information on Cal Orck'o is extremely spotty, and the website for the site doesn't seem to have an "English" option.  My Spanish skills are pretty rudimentary at best, but I think I was able to come up with a list of the dinosaurs whose tracks are preserved at Cal Orck'o.  Now, keep in mind, very rarely do you definitively know what animal made a fossilized footprint, and most of the time these are simply good guesses.  For the picture below, I used ones taken from the garden area thing at the Cal Orck'o museum.  So if you are going to blame someone for inaccurate data, make sure you blame them and not me!

An abelisaur, a type of carnivorous dinosaur like Abelisaurus or Carnotaurus.

An iguanodont, a type of herbivorous dinosaur like Iguanodon.

A ceratopsian, a type of dinosaur like Triceratops or Protoceratops.

An ankylosaur, a type of dinosaur like Ankylosaurus.

A titanosaur, a type of sauropod dinosaur like Saltasaurus.

A dromaeosaur, a type of carnivorous dinosaur like Velociraptor.

A ceratosaur, a type of carnivorous dinosaur like Ceratosaurus.

A hadrosaur, a type of herbivorous dinosaur like Parasaurolophus.

A tyrannosaur, a type of carnivorous dinosaur like Tyrannosaurus.

Again, keep in mind that I have next to no idea which of these, if any, were found at Cal Orck'o.  I plan on doing a little bit of digging within the next few weeks, so hopefully I will be able to get back to you sometime soon!

Cochabamba on Dwellable

Top Ten: Extinct Sea Monsters (Part 5 of 5)

Our final edition of "Top Ten:  Extinct Sea Monsters!

9.  Tanystropheus - Living during the Middle Triassic Period, Tanystropheus is somewhat of a misfit amongst this group, as he is not really a sea-monster, and was, at most, a semi-aquatic animal (think otters).  Purportedly piscivorous, Tanystropheus fossils are usually found in semi-aquatic sites.  Its neck has been likened to that of the Plesiosaurs, like Elasmosaurus.  They would all use their necks to surprise a group of fish, long before the fish would be able to see the body of the reptile. Remains have been discovered throughout France, Germany, and Italy, amongst other places. 

10.  Tylosaurus - Interestingly enough, the closest living relative of the extinct mosasaurs, of which Tylosaurus is a member, are the monitor lizards, like the Komodo dragon.  Both the monitor lizards and the mosasaurs have a third eye on the top of their heads, although it just looks like a little white dot on the top of the head of the monitor lizard.  It doesn't work in the same fashion as their other eyes, however.  Look towards a light (not the sun, because apparently that can actually be harmful) and close your eyes.  You can still still some light, right?  Now, move your hand back and forth in front of your face, between your eyes and the light.  Can you see how the light changes?  You can't see anything more distinct than the fact that something moved between you and that light.  That is what the third eye of monitor lizards and mosasaurs would have been like.  Tylosaurus also inhabited the Western Interior Seaway during the Late Cretaceous.  Remains, amongst other places, have been discovered in Alabama and Kansas, amongst other places.

So that concludes our "Top Ten:  Extinct Sea Monsters" edition!  Unfortunate that we had to break it up into five parts, to be sure, but hey, that's life!

This post is part of the "Top Ten: Extinct Sea Monsters" series.  For the rest of the posts in this series, click HERE.  

Top Ten: Extinct Sea Monsters (Part 4 of 5)

7.  Archelon - Archelon is the largest sea turtle that has been discovered to date, the closest living relative that Archelon has is the "Critically Endangered" leatherback sea turtle, the largest sea turtle alive today.  Living in the Late Cretaceous Western Interior Seaway between 75-65 MYA, Archelon has been discovered in the states of South Dakota, Wyoming and Kansas. 

8.  Leedsichthys - Often cited as the largest fish known to humankind, the largest Leedsichthys had an estimated length of 72 feet, but some researchers believe that it could have grown to sizes that would rival those seen in the blue whale, the largest known animal ever to live on planet Earth.   Although Leedsichthys swam the seas only during the Jurassic Period, the group that it belonged to survived until the end of the Cretaceous Period.  Remains of this filter feeder have been uncovered in England, France, Germany, and Chile.  


COMING UP NEXT WE HAVE:

9.  Tanystropheus
10. Tylosaurus

This post is part of the "Top Ten: Extinct Sea Monsters" series.  For the rest of the posts in this series, click HERE.  

Top Ten: Extinct Sea Monsters (Part 3 of 5)

 5.  Elasmosaurus - Next up on our trip across time is Elasmosaurus.  One of the largest of the Plesiosaurs ever discovered, Elasmosaurus grew up to 46 feet long, which was about half neck.  Equipped with a fairly small head, Elasmosaurus would have been incapable of going after large prey, so it would have mostly stuck with fish.  Elasmosaurus lived during the Late Cretaceous, a time when much of North America was "Beneath the Waves," under something that we call the "Western Interior Seaway."   Remains of this animal were first uncovered in Kansas, but it almost certainly swam all over the seaway, including in Colorado.

6.  Dunkleosteus - Dunkleosteus, a creature we talked about a few weeks ago in our post about the Coelacanth, is another fascinating animal.  Almost thirty-five feet in length, Dunkleosteus was a member of the Placoderms, a group of armored fish that were only around for about 50 MYA.  A long time, to be sure, but not very long compared to the 400 million year reign of the sharks.  While the Placoderms themselves lived during the Silurian and Devonian Periods, they went extinct during the transition to the Carboniferous Period, at the end of the Devonian.  Dunkleosteus fossils have been discovered in North America, Poland, Belgium, and Morocco.

 COMING UP:

7.  Archelon
8.  Leedsichthys
9.  Tanystropheus
10. Tylosaurus

This post is part of the "Top Ten: Extinct Sea Monsters" series.  For the rest of the posts in this series, click HERE.  

What REALLY Killed the Dinosaurs?

Today, almost all paleontologists believe in one of two scenarios that brought upon the downfall of the dinosaurs; the Silver Bullet Hypothesis, and the Blitzkrieg Hypothesis.  Proponents of the Silver Bullet Hypothesis consider the asteroid that hit Mexico 65.5 MYA to be the cause of the dinosaurs extinction, while fans of the Blitzkrieg Hypothesis believe that the asteroid worked in concert with other factors, like a number of extraordinarily large volcanic impacts and receding sea levels.  Although both of these hypotheses hold great weight, and stand up well to investigation, I find myself more in the Silver Bullet camp.  (If you are unsure, check out this video: http://www.youtube.com/watch?v=5gqq2rgOmi8 .  It's a bit long, but you can skip parts of it and still get the gist.  I was simply blown away after watching it, and landed smack-dab in the center of the Silver Bullet camp.)

However, this post is not to talk about the merits of the generally accepted dinosaur-death hypotheses; just like the post regarding the oddly named animals (http://thenaturalworld1.blogspot.com/2012/07/masiakasaurus-knopfleri-and-other.html), Scott Sampson's book Dinosaur Odyssey had another especially interesting tale, a tale about the many different hypotheses (over one hundred in all!) about how the dinosaurs died from over the years.  Here are some of the more interesting ones, quoted from Scott Sampson's book:

1.   Disease
2.   Slipped Vertebral Discs:  Because dinosaurs were so big
3.   Loss of Interest in Sex
4.   Poisonous Plants 1:  The consumption of these plants led to a deadly diarrhea amongst the dinosaurs
5.   Poisonous Plants 2:  The consumption of these plants led to a deadly constipation amongst the dinosaurs
6.   Fungal Invasions
7.   Climatic Change 1:  Global Warming
8.   Climatic Change 2:  Global Cooling
9.   Cosmic Radiation From a Supernova
10.  Egg-Eating Mammals
11.  Sunspots
12.  Nasty Aliens
13.  Not Enough Room on Noah's Ark
14.  The Racial Senility Hypothesis:  Dinosaurs, as a group, were young and restless when they first appeared in the Late Triassic Period.  During the Early Jurassic, the dinosaurs experienced "adolescence," as they expanded "in both form and diversity."  When they reached the Late Jurassic and Early Cretaceous, the dinosaurs had "reached their evolutionary peak;" they were middle-aged, and had nowhere to go but down.  Thus, in the Late Cretaceous Period, when the dinosaurs like Triceratops, Parasaurolophus, and Pachycephalosaurus grew interesting crests, frills and the like, these were "the result of hormones gone wild and certainly symbolic of a group on its way out."

Obviously, some of these solutions are more interesting than others, but all of them are, at this point in the study of dinosaurs, outdated.  But who knows: perhaps, someday soon, someone will discover proof that it was aliens, and not an asteroid, that ultimately did-in the dinos.

Masiakasaurus knopfleri, and Other Interestingly Named Creatures

A few months ago, while reading Dr. Scott Sampson's book Dinosaur Odyssey (you probably know him as the guy from Dinosaur Train), he has a very brief section of his book where he talks about some interesting scientific names of sometimes not that interesting of creatures.  He presents nine of them, and here I present them to you, as well.

1.  Masiakasaurus knopfleri
This dinosaur, from Late Cretaceous Madagascar, was named by Scott Sampson and his colleagues, means the "vicious lizard of Knopfler," meaning Mark Knopfler, a famous musician.

 2.  Milesdavis zlichovianus
This trilobite was named after the famous jazz musician Miles Davis.

3.  Mozartella beethoveni
This wasp was named after two famous classical musicians, Wolfgang Amadeus Mozart and Ludwig van Beethoven.

4.  Dicrotenipes thanatogratus
This one is probably less obvious to most of you out there, but in Greek, thanatos means "dead" (think Thanos, the villain for the next "Avengers" movie from Marvel: he loves and worships death), and in Latin, gratus means "grateful."  This midge was named after the famous band, Grateful Dead.

5.  Montypythonoides riversleighensis
This extinct Australian snake was named after the Monty Python franchise, but unfortunately, the name is now outdated; its correct scientific name now is Morelia riversleighensis.

6.  Strigiphilus garylarsoni
Named after the famed cartoonist Gary Larson of The Far Side fame (watch for at least one post featuring him next week).  Besides having this owl louse named after him, also has had a beetle and a butterfly named in his honor. Regarding the owl louse, he said “I considered this an extreme honor. Besides, I knew no one was going to write and ask to name a new species of swan after me. You have to grab these opportunities when they come along.”

7.   Ninjemys oweni
"Owen's Ninja Turtle" is named after the famous group, the Teenage Mutant Ninja Turtles, and was found in Pleistocene-aged rocks in Queensland, Australia.

8.  Gozillus

http://www.csmonitor.com/Science/2012/0425/Mysterious-Godzillus-fossil-find-stumps-scientists

9.  Darthvaderum greensladeae
One of my personal favorites, this mite was named after the famous Darth Vader, from Star Wars.

Convergent Evolution: Hesperornis and Penguins

Everyone who is reading this blog, and most people who aren't, have heard of penguins, and know, more or less, what they look like.  However, most people have no idea what a Hesperornis is, which is entirely forgivable.  What is especially interesting about Hesperornis is that it was really the "original penguin," in the loosest sense of the terms.

If not for the captions below each picture, these two animals would most likely be quite difficult to tell apart.  One major difference between the two birds is in the mouth: Hesperornis had teeth, a feature which no modern birds possesses.  Another major, but non-skeletal difference, between the two birds is that Hesperornis died out 78 MYA, during the Late Cretaceous.  Its remains have been found in the United States (Kansas), Canada, and Russia.

The similarities between Hesperornis and modern day penguins is called "Convergent Evolution," a fascinating topic which we will undoubtedly touch upon numerous times.  According to Science Daily, convergent evolution is, "In evolutionary biology, convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches."  In English, when two animals, not necessarily closely related at all, evolve similar features that serve the same purpose.

An (excellent) drawing of the skull of Thylacosmilus

 Another example which we have already talked about is the long, saber-like canines that evolved in both the saber-toothed cats, such as Smilodon, and the South American marsupial carnivore Thylacosmilus.

 This post is part of the "Convergent Evolution" series.  For the rest of the posts in this series, click HERE.

Fossil Hunting 6/30

Yesterday, my friend Masaki Kleinkopf and I went to check out a fossil site that I had found with another friend a couple of days ago. It looks to be Laramie Formation (towards the end of the death of the dinosaurs, in the Late Cretaceous), and a river seems to have been in this area. The most exciting fossilized things we found was a bunch of fossilized wood, as you can see below.

Fossilized wood

More fossilized wood

However, the most exciting that we saw of the day was definitely a wolf spider, probably three inches across. We saw the web first, and I was going to try and get the spider to come out with a long piece of grass (didn't want to get too close!) when I accidentally startled a grasshopper into the web. It couldn't get out, and suddenly the wolf spider appeared, and attacked it. It ran up probably ten or fifteen times, stabbing the grasshopper with its mandibles (I think that's what it was doing, anyways) and with its two front legs held up in the air. After awhile, the grasshopper was still alive, and the wolf spider retreated back down its hole. When we came back fifteen or so minutes later, the grasshopper was gone; probably dragged down by the wolf spider into its burrow to be devoured. I took a pic of the spider, but I think the  spider moved when it saw my phone, so all you can see is a blurry shot of the burrow.

Wolf spider burrow.  I think that the darker black in the burrow might be the  spider.

Besides wood, the Laramie Formation has yielded a number of dinosaur remains as well, among them being Edmontosaurus, Ornithomimus, Thescelosaurus, Triceratops, and Tyrannosaurus.  But first, here is a map of where the Laramie Formation is in Colorado.  Many of the dinosaurs that I mention below were found up in the north, near Fort Collins I believe.