Gulf Fritillary, Agrulis vanillae incarnata |
Tuesday, October 29, 2013
Gulf Fritillary
Thursday, October 24, 2013
Purple Passionflower
Purple Passionflower, Passiflora incarnata |
Tuesday, October 22, 2013
Blazing Star
Blazing Star, Liatris |
Thursday, October 17, 2013
Western Interior Seaway
Scallop, Kingena wacoensis and Brachiopod, Neithea texana [Grayson Formation, Lake Arlington, Texas] |
The Western Interior Seaway was an extensive epeiric sea formed from the high sea levels between the middle and late Cretaceous Periods over 75 million years ago. It once covered most of the Midwest of North America with many present day states once completely submerged. A vast number of marine fossils, from vertebrates to molluscs, have been unearthed in these regions.
Devil's Toenail, Exogyra ponderosa [Anacacho, Uvalde County, Texas] |
The widespread and well-preserved fossils of marine fauna has allowed for the environment of the Western Interior Seaway to be determined. For the majority of its existence, water column stratification gave way to dysoxic to anoxic bottom-water environments. These conditions led to a number of opportunistic and low oxygen adapted taxa to emerge. There was also a predominance of brackish-water conditions on the surface. As the inland sea stretched from the far north down to the tropics, there was a mixing of cooler, less saline waters with warm tropic waters resulting in a limited presence of typical marine organisms.
Tuesday, October 15, 2013
Lobsters
A lobster is an invertebrate with a hard, protective exoskeleton. They need to molt in order to grow, a process that may change the color of the animal in some species. Their unequal claws can be categorized as the smaller ripper claw to tear soft flesh and the larger crusher claw to pulverize shells. While the claw types can be either left or right, males generally have larger crusher claws than females.
Clawed lobsters belong to the family Nephropidae. They have existed at least since the Cretaceous period over 140 million years ago; however, the ancestor of lobsters and scorpions, Kooteninchela deppi, has fossil records spanning at least 550 million years. During the Cretaceous period, at least 53 species existed whereas during the Tertiary period, only 18 species have been identified. Currently, at least 29 species exist and have been recorded worldwide.
Tomorrow, October 16th, 2013, is National Fossil Day. As I only post twice a week, and not on Wednesdays, I declare this fossil week where I'll post my final fossil pictures - until the next batch :)
From the newest fossil collection at the Heard Natural Science Museum and Wildlife Sanctuary.
From the newest fossil collection at the Heard Natural Science Museum and Wildlife Sanctuary.
Tuesday, October 8, 2013
Passenger Pigeon
Passenger Pigeon, Ectopistes migratorius |
Stool pigeon is a term derived from these birds as hunters would mount a live passenger pigeon on a stool. This pigeon would then cry to its brethren for help allowing for easy prey. A famous hunt in Petoskey, Michigan in 1878 recorded at least 50,000 kills each day for nearly five months. By the time regulations were finally in place, too many had been killed and too much habitat removed for passenger pigeons to ever recover. While there were still thousands in the wild, they were no longer in a situation where they could breed, and passenger pigeons slowly died off. The species was officially declared extinct in 1914 when Martha, that last living passenger pigeon known who lived at the Cincinnati Zoo, died.
”It is not always necessary to kill the last pair of a species to force it to extinction.” - Paul R. Ehrlich
In the late 1800s, the Lacey Act was established in part due to the nearing extinction of passenger pigeons at the time. The law prohibits illegally obtained game to be shipped across state boundaries. In 1918, the Migratory Bird Treaty Act was passed to protect all native birds to the highest degree. By federal law, one must have a permit to possess any native bird or bird parts including, but not limited to, feathers, nests, mounts, and eggs. While the lessons of the passenger pigeon extinction have not been learned everywhere around the world, there has been progress in species protection.
For another, slightly different write-up I've done on Passenger Pigeons, you can see my Google+ post. This beautiful, preserved mount is currently on display at the Heard Natural Science Museum and Wildlife Sanctuary.