Ammonites 101

Hello comrades! Today's post will be about ammonites.
        I was planning to make this post about one specific species of ammonite, but there were just so many different kinds, that I thought it would be more interesting to talk about the entire order of ammonites and their fascinating multiformity. First of all, ammonites are obviously not dinosaurs, so this goes under that whole "things" category. They are a specific order of aquatic animals belonging to the phylum mollusca, the same one that including squid and snails. They were common throughout the Mesozoic Era, the same time as the dinosaurs. The whole order went extinct at the same time as the dinosaurs as well. Their closest living relative today is the nautilus, which looks similar to how many scientists today think an ammonite would have looked in life.
        Ammonites came in a surprisingly diverse variety of shapes and sizes. The most famous of these shapes being the coiled spiral or "evolute serpenticone." There are technical terms to describe pretty much every conceivable variation of this shape, so a guide is included below.

       Ammonites could be enormous or incredibly small depending on the species. Serpenticone's like Promicroceras were only 1.5 cm across, whereas others like Parapuzosia were 2.6 meters across! These are always just the shells that are found as fossils. The soft bodied parts obviously could not survive the fossilization process. The shells were composed of aragonite and so are quite durable. Ammonites would've eaten small prey like minnows and isopods, which are small swimming crustaceans. Depending on the thickness of their shells they could have swam to all sorts of different depths.

       That's that for ammonites. The next post will be on some kind of dinosaur.

-Athos

Monks, Neale, and Philip Palmer. Ammonites. Washington, D.C.: Smithsonian Institution, 2002. Print.

Nasutuceratops Titusi

        Hey guys, today's post is about the recently discovered Nasutuceratops!

        Nasutuceratops was a Late Cretaceous dinosaur belonging to the family ceratopsidae, the same family as the famous Triceratops. The animal was about 4 meters long, 1.5 meters tall, and a ton in weight. It was discovered in Utah, which was, during the Cretaceous period, an enormous area of swamp land. This ceratopsid made a bit of a stir in the media thanks to its unusual name, which translates from latin to mean "Big nose horned face." However it is not the dinosaur's nose that is most peculiar, many other members of this family such as Pachyrhinosaurus had similar large sets of nares. It is the horns that make Nasutuceratops unique. Here's a comparison with Triceratops, see if you can spot it.

I drew those arrows myself. I'm so talented.

        It's the horns. Nasutuceratops had horns that, unlike the rest of its family, stuck horizontally down its face. These horns are confusing, since unlike other ceratopsids, they could not use them as self defense. On Triceratops, for example, the horns are pointing up, so if there was a large predator like a Tyrannosaurus, it would be able to thrust out its head and gore the enemy. Nasutuceratops' horns are not at an angle that would allow it to gore anything, and even if it tried to attack something lower down, its beak would get in the way. In my opinion, Nasutuceratops' genus probably evolved to have more head butting contests than its evolutionary siblings, contests in which large forward pointing horns could be broken or damaged. These flatter-to-the-face horns would also help to cushion blows when ramming each other. In this manner, they would be more like a Pachycephalosaurus in their mating and territorial disputes, rather than the rutting behavior scientists believe other members of ceratopsidae would have engaged in.

    (click to enlarge)

   And that about wraps up today's entry. Next time it will probably be an ammonite or something. I haven't done one of them yet.

-Athos

For this one:

http://content.lib.utah.edu/cdm/ref/collection/etd3/id/528

Brachiosaurus

Hello comrades, today we'll be covering a better known dinosaur, brachiosaurus.

        Brachiosaurus was a late Jurassic sauropod. It was first discovered during Edward Drinker Cope and Othniel Charles Marsh's famous "Bone Wars." Marsh discovered a skull of the beast in Colorado, and from this one bone he eagerly classified it as a new species in an attempt to beat out Cope. He then proceeded to idiotically place the skull on the body of an apatosaurus and call it a brontosaurus, opening a sardine can of confusion in nomenclature that would carry on even until today. Congratulations on your fantastic legacy marsh.

         Brachiosaurus would've fed on leaves from the tallest of trees. It was able to reach them thanks to its enormous 32 foot long neck. The neck was so huge that each vertebrae was 3ft and 3in in length. This isthmus of an esophagus would allow it to reach higher than any other known organism. This neck was also incredibly heavy, so brachiosaurus needed some of the strongest front legs in the animal kingdom to keep it up. These front legs were noticeably longer than the back, and this sauropod needed the strong limbs to keep its body from collapsing, so Jurassic Park's famous bipedal brachiosaur is a little inaccurate.

        Another striking feature of brachiosaurus, as you can see from the good doctor up there, was it's head crest. A wall of bone ran down the middle of the dinosaur's head, separating the nasal cavities. These huge nostrils would perhaps given the beast a good sense of smell, although what it would use this sensitivity for is unknown. 

       And that's it for today, next time will be about nasutoceratops, which will also be the blog's first ceratopsid.

- Athos

Palmer, Douglas, Simon Lamb, Guerrero Angeles. Gavira, and Peter Frances. Prehistoric Life: [the Definitive Visual History of Life on Earth]. New York, NY: DK Pub., 2009. Print.

(MLA format is just my favorite thing ever)

Ophthalmosaurus

Hello everyone, sorry about the lack of posts, and the lack of sauropod in this post. I just got back from vacation in florida, so I decided I would make a post about something that lived in florida. That something is Ophthalmosaurus.

        Ophthalmosaurus was a jurassic ichthyosaur about 19.5 feet long. It fed on squid and other small marine life. It had a long toothless beak, which would have been ideal for squid and other soft bodied animals. Another interesting fact about this animal is that it gave birth to live young underwater. These baby Ophthalmosaurus would emerge tail first to prevent drowning. Ophthalmosaurus had thick bony plates surrounding it's extraordinarily large eyes. These plates are called sclerotic rings, and aid in supporting the eye.
     Several of the sources I read stated that an Ophthalmosaurus would swim to a maximum depth of 600 meters. To me, this seemed a rather small number, so I decided to compare this depth with some modern day air breathing hydrophiles, the whales. I chose the species most similar in size to an Ophthalmosaurus, the Short-Finned Pilot Whale, or Globicephala macrorhynchus. These modern day sea giants can swim to a depth of 1000 meters, with nothing but a breath of air and some relatively strong bones. Using this information, I approximate that an Ophthalmosaurus could dive to a depth of around 1300 meters. Being a reptile, Ophthalmosaurus has a slower breathing rate than it's modern day equivalent, so it could spend more time swimming down. The enormous sclerotic rings of the Ophthalmosaurus also bring me to believe it could swim deeper than a pilot whale, as these rings could help keep the soft vulnerable eyes safe from pressure changes. Diving deeper would also account for the fact that the eyes were huge, these would be necessary in the low light. This depth would also place an Ophthalmosaurus in the top layers of the bathypelagic zone, home to more soft bodied organisms which Ophthalmosaurus' toothless beak could easily prey on. 1300 meters makes more sense because of the Ophthalmosaurus' body, and is not at all unreasonable looking at the depths of some air breathing underwater animals, such as the sperm whale, which can swim to depths of 3200 meters.

  That about wraps up today's ancient organism. Next time it'll be a sauropod, I promise.

-Athos

Thanks for the information goes to:

WHOI : Oceanus : Pilot Whales the 'Cheetahs of the Deep Sea'

http://www.abc.net.au/dinosaurs/fact_files/sea/ophthalmo.htm