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.

The Fauna of South Carolina: Reptiles and Amphibians

First off, don't forget to look below to see the answer to last weeks mystery animal, and to see a couple of pictures of this weeks!

Recently, my family visited some good friends of ours in South Carolina for a few weeks.  Not only did we have a lot of fun visiting them, we saw a lot of cool plants and animals there that we simply don't have up north!  For some of you, many of these animals and plants will be routine and boring, but hopefully there will be something in here that you will find interesting!  I think I am going to split this post up into at least a few different segments, with tomorrows post devoted entirely to the Black Skimmer, a very interesting bird that I had the good fortune to see hunt!  So today I am going to talk about some of the interesting reptiles and amphibians we saw down there, and over the next few weeks we can take a look at some of the birds, fossils and other things we saw down there!

Due to the increased heat and humidity, coupled with less of a swing between the seasons (i.e. it rarely snows and drops below freezing), the south is an excellent place to see all sorts of reptiles and amphibians.  We saw a number of turtles and a frog/toad or two when we were in the south, but what interested me more were the lizards.

A Carolina anole (Anolis carolinensis).  Despite its name, the Carolina anole is found in both South and North Carolina, as well as Florida, Georgia, Louisiana, Texas, Alabama and Mississippi.

A type of skink, but I have yet to ascertain its species, although I am almost certain its genus is that of Plestiodon

And then, of course, there's the gators.  The American Alligator lives in the same states as the Carolina anole, as well as Virginia, Arkansas and Oklahoma.  While we did see a few in the wild, all of these shots (except for that of the gator footprint) were taken at a place called Brookgreen Gardens, or at a restaurant called the Crab Shack.

This big gator we saw at Brookgreen Gardens

This is a picture of a gator footprint that I took.  You can see three of the toes very well, making it look a lot like a theropod dinosaur track, but you can see the other two toes as little holes in the ground.

This picture, and all the rest, were taken at an awesome (both food- and entertainment-wise) restaurant on Tybee Island in Georgia called The Crab Shack.

 

 

 

 

 

 This post is part of "The Fauna of South Carolina" series.  For the rest of the posts in this series, click HERE.

Sea Pines on Dwellable

What Is It? The Weekly Challenge #1 Answer

Well, it's that time of the week again!  We only had a few guesses this week, and no one got it exactly right, but there were some close guesses!  The two closest were Kristie C., who guessed an Adélie Penguin, and Masaki K. who guessed Cormorant.  Well, the correct answer to last weeks challenge is Waimanu.  Waimanu is the scientific name of the oldest known fossil penguin.  Two species are known, and both of them were found on the South Island of New Zealand.  One of the species, Waimanu manneringi, lived during the Paleocene, around 61.6 MYA; that means that the oldest known penguin was swimming the oceans only a few million years after the death of the dinosaurs!  Although Waimanu manneringi is the oldest KNOWN fossil penguin, it by no means is the oldest penguin.  In fact, it is quite likely that, were scientists to uncover a fossil that shows when penguins split off from the other orders of birds, we would not even recognize it as a penguin.  Waimanu had undoubtedly already adapted to a fully non-aerial lifestyle, and almost certainly behaved much like modern penguins do when it comes to breeding on land, near the ocean.


Works Cited:

Waimanu, the first penguin. (2010, January 30). Retrieved July 11, 2012, from https://fossilpenguins.wordpress.com/2010/01/30/waimanu-the-first-penguin/