Life Through Geologic Time

Microceratus

Microceratus was an early Ceratopsian dinosaur, and was one of the earliest ceratopsian dinosaurs, along with Psittacosaurus (you know, that guy that was recently discovered with the spines(Which I should have done instead, it would have been much easier to get images.)). It was found in Asia, and, like many early dinosaurs, was bipedal. It was an herbivorous, like all ceratopsian dinosaurs, and it likely fed on ferns, cycads, and conifers, which were the predominant vegetation in the area. Its original name was Microceratops gobiensis, and was first described in 1953, but the generic name was already occupied by an ichneumon wasp, of all things. Many specimens have since been reassigned to Graciliceratops, however, the name Microceratus was proposed for the type specimen in 2008 and has stuck with it.

Okay, so it was really hard to get this drawing, and I could not find any fossil images, I’m sorry. Image is copyright of DeAgostini.

Alright, friends, let’s talk about evolution. FIRSTLY, I MUST SAY THIS, AND I MUST SAY IT IN BOLD AND CAPS LOCK, THE ABOVE PICTURE IS NOT EVOLUTION, IT IS AN ACCIDENT THAT LIKELY AROSE FROM THIS IMAGE:  Now that that’s said, let’s talk about evolution, and its process, natural selection.

Evolution:

Evolution is change with descent. Now what does that mean, “change with descent”? Well, change with descent is just how organisms change genetically with descent, that is, how organisms’ offspring change from the organisms which they arose from. IT IS NOT “PROGRESS,” AND IT IS FOOLISH TO THINK IT IS, EVOLUTION IS THE ADAPTATION TO A LOCAL AND CHANGING ENVIRONMENT, OR, MERELY, GENETIC CHANGE WITH DESCENT (as stated (repeatedly) above.)

Natural Selection:

Contrary to what many believe, Natural Selection is not the same as Evolution. Natural selection follows three relatively undeniable principles, which are as follows:

Variation: Life varies. Whop-dee-doo. I am different from every other Homo sapiens sapiens and there’s nothing you can do about it. Coincidentally, I am also different from every armadillo, but we’ll talk about that later if you’re good.

Heredity: When a mommy and a daddy get “it” on, and their genes cross and get together, they make a new sequence that probably never existed before then. This is, of course, true only for organisms that sexually reproduce. Occasionally asexual organisms will make babies with themselves, but this doesn’t usually yield any genetic change. When it does, however, whoop-dee-doo, we have a new organism that has a new DNA sequence

Superfecundity: I particularly like this principal because it’s fun to say and is, some might say, a bit morbid. Superfercundity is the principle that more offspring are produced than could ever possibly survive to adult hood and mate to make more little organisms. 

The Inference: The inference is that, on average, the organisms better suited for their local and changing environment will survive to pass on their traits, but not necessarily, as something may happen to an organism, it could fall off a cliff, be run over by a car, be attacked by a starving horde of flesh eating slugs, et cetera. If said organism does pass on its genetics, the offspring will, on average, look similar to the parents, yet different.

Sauropelta (Shielded Lizard), not to be confused with Scutosaurus, was a nodosaurid, a heavily armoured, quadrepedal, herbivore, and yes, a dinosaur, related to ankylosaurus. With its body covered in hard, boney plates (osteoderms) and with speacialized ones that came to a point on Sauropelta’s neck, it was a formidable creature.  It’s tail could have been comprised of as many as fifty vertebrae and made up half of its body length.There were some fundamental differences between it and other nodosaurids, though. Its legs were longer, meaning that it was likely capable of a jog of sorts, and it didn’t have a clubbed tail.

Scutosaurus (Shield Reptile), not to be confused with Sauropelta was a large, armoured, herbivorous pareiasaur, which is a synapsid that lived in the Permian with stocky bodies, short tails, and highly sculpted and adorned skulls. That’s right, synapsid, not dinosaur. Learn more about synapsids with my here. Scutosaurus is found in the Russian Permian beds, with some found standing, suggesting that they got stuck in mud or swamps while feeding. It was likely aquatic, but being that many fossils have been found mired in mud, it may be unlikely. Unlike most reptiles, Scutosaurus held its legs beneath it to support its great weight, rather than side sprawling, only endothermic vertebrates are known to do this today. It likely had well developed hearing due to a slender bone found in its ear.

Tanystropheus (long-necked one) has, since its discovery, has confused scientists about how it led its life with such a neck. Scarf shopping must have been impossible, that neck is as tall as a man! It’s neck had from anywhere between 8 and 12 extremely elongated vertebrae, with a chinese species having a possibility of 27. The neck bone’s connected to the neck bone, the neck bone’s connected to the neck bone, the neck bone’s connected to the neck bone, and so on and so forth. We can tell the difference between sexes because of extra tail bones in certain specimens that are speculated to support a brood pouch for raising young (kind of like a marsupial). It is unknown what kind of lifestyle Tanystropheus had, one specimen found in 2006 was so well preserved that there were traces of skin found with overlapping, non-rectangular scales. The aquatic sediments in which it was found, combined with that enormous neck, have led some to believe that it is an aquatic creature, but its feet are better formed for terrestrial lifestyles. As such, it is hypothesized that juveniles, which had more varied teeth, originally led a terrestrial lifestyle, which then gave way to an aquatic lifestyle, which may have connected to a change in diet (i.e. fish).

Libonectes (Southwest Swimmer) was a very long-necked plieosaur, known as an elasmosaur (a group of marine animals from the creatcious with four strong paddle-shaped limbs that lived in the sea.)  An early fossil hunter thought that libonectes’s head was originally the tail of another fossil, then it was thought that their necks could move much like a snake’s body, but they are actually relatively rigid, much like those of sauropods.  There were 62 bones in its long neck, which accounted for over half of its body length. Libonectes likely swam after shoals of fish and attacked from underneath to trap them in its cage like mouth. Its teeth were long, sharp, forward facing, and interlinked forming said cage for trapping its unfortunate prey.

Mononykus (single claw, so named for its single digit fore-limbs) is amazingly closely related to birds, and yet, is still a theropod dinosaur. It roamed open desert plains, and, because of its light, hollow bones, fossil specimens are frustratingly incomplete. It had large, keen eyes, and, as such, is likely to have been (at least) partially nocturnal. It had strong legs, making it a swift predator, and it likely fed on plants as well as lizards and insects. Those arms! That finger! What could they have been used for? Paleontologists speculate that Mononykus used those surprisingly muscular arms and fingers to break open termite mounds in search of food, rather than for snatching prey or digging.

Hesperornis (Western Bird) was one of the largest birds of the age of dinosaurs. On land, it would have moved much like how penguins do today, not waddling mind you, but scooting along on its belly. It may have nested on isolated islands, or live birthed in the water. It’s webbed feet that faced backwards were ide3al for swimming and diving. It may have been one of the greatest (most well-adapted) predators of the ocean. It had many sharp teeth for gripping prey, a feature lost to birds after the mesozoic (excepting the occasional retroactive gene.) It could not fly, ans would be about the same size as an average sized man. It can be found in the North American Inland Sea, theTurgai Straight, and the North Sea regions in North America.