July 27, 2010
I’ve mentioned Safari Ltd. a few times already on this blog (here and here, for example), so I probably don’t need to tell you that they tend to leave any competition in the dust when it comes to producing museum-quality plastic animal reproductions. One of their flagship brands is the Carnegie Collection, a line of toy dinosaurs and other prehistoric creatures that first came out in 1989. Originally based on fossils from the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, the design of these replicas has become increasingly detailed and scientifically accurate over the years. Most of these figures are scaled 1:40, but there are exceptions, such as the 1:10 scale Ichthyosaurus, which just came out last month.
The Safari Ichthyosaurus is 8 inces long and painted with a color pattern similar to the modern Common Dolphin (Delphinus). The coolest feature of this sculpt is, of course, the Mesozoic ammonite gripped tightly in its jaws.
Ichthyosaurs (“fish lizards”) were a group of highly-specialized marine reptiles that dominated the world’s oceans for much of the Mesozoic era. They were most definitely not dinosaurs…but you knew that already, right? Appearing in the fossil record in the first part of the Triassic period (~245 million years ago), ichthyosaurs thrived during the Jurassic, but they went extinct before the end of the Cretaceous period, about 90 million years ago. Their fish-like body shape is often compared to that of modern dolphins as a classic example of convergent evolution. Fossil stomach contents show that some species definitely preyed on ammonites and belemnites, and it’s likely that cephalopods were an imporant part of a balanced breakfast for most ichthyosaurs.
The genus Ichthyosuarus itself, which lived in the Early Jurassic seas that covered what is now southern England and continental Europe 199-189 million years ago, was first discovered in early 1800s. These finds, including many complete skeletons, played an important role in how we came to understand the age of the earth and helped define the then brand-new science of paleontology.
I picked this up from the gift shop of the NC Museum of Life + Science (along with Cryolophosaurus, this year’s other new Carnegie dinosaur) as a birthday present for myself. Suggested retail is $8.99, and if you don’t have access to a museum gift shop or speciality toy store, you can order it online from Amazon.com or directly from Safari.
May 28, 2010
I’m still in a paleontological mood after yesterday’s big news, so here is another big fossil…literally. Parapuzosia seppenradensis is desmoceratid ammonite from Late Cretaceous Germany, and it is the largest known ammonite species. An incomplete specimen found in 1895 had a diameter of 1.95 meters (~6 ft), and in life it is estimated to have been 2.55 meters (over 8 ft) across.
As big as P. seppenradensis was, it was by no means the largest prehistoric cephalopod. That honor goes to the giant Ordovician orthoconic (i.e. straight-shelled) nautiloid Cameroceras, which may have been as much 11 meters long (~36 ft). Of course that is the topic for another post…
May 27, 2010
Today it was announced in the journal Nature that the mystery of Nectocaris pteryx, a problematic fossil species from the famous Burgess Shale deposits, has finally been solved. This tiny Invertebrate that lived in the Cambrian oceans 500 million years ago is, in fact, the oldest known cephalopod.
[UPDATE: The image I originally used in this post seems to have been removed from Wikipedia Commons. Follow this link to see before and after reconstructions.]
The original Nectocaris specimen was discovered 100 years ago, but it wasn’t formally described until 1976. However, the phylogenetic identity of the two inch long creature remained uncertain. It seemed to have similarities to both arthropods and chordates, but didn’t clearly fit into any known group. In this new report, researchers Martin Smith and Jean-Bernard Caron examined 91 additional specimens and came to the conclusion that N. pteryx is a mollusk, specifically a primitive, non-mineralized (i.e. shell-less) cephalopod. This revelation pushes the origins of cephalopods back at least 30 million years.
As we can see from the above reconstruction, Nectocaris resembled a modern cuttlefish. It had a flat “kite-shaped” body with large lateral fins, but only a single pair of long, grasping tentacles. It had a pair of non-faceted eyes on short stalks and a large anterior funnel, suggesting that cephalopod jet-propulsion evolved very early on. The lack of a shell disproves a long held assumption that shell-lessness is a relatively recent adaptation. It now seems that cephalopods didn’t evolve shells until much later, most likely “in response to increased levels of competition and predation in the Late Cambrian.”
October 23, 2009
This awesome replica of a turrilitid ammonite is from the Cretaceous Seas diorama at the American Museum of Natural History in New York City. I don’t know exactly which type of turrilitid this is, but my best guess is the genus Pseudhelicoceras.
Members of the ammonite family Turrilitidae are characterized by shells that are not typical tight spirals—a condition known to paleontologists as heteromorph. It isn’t clear what ecological niche the turrilitids filled, but at least some species are thought to have drifted up and down in the water column. They lived world-wide during the late Cretaceous period, but, like all ammonites, they went extinct in the same global catastrophe that killed off the dinosaurs 65 million years ago.
August 18, 2009
OK, so this doesn’t have anything to do with Cthulhu Week, but I thought this story was cool enough to break protocol.
Paleontologists in the UK have discovered a fossilized cephalopod so well preserved that the creature’s ink sac was still intact. In fact, scientists were able to extract a portion of the ink and use it to draw a picture of what the creature looked like when alive!
The 150 million year old fossil of Belemnotheutis antiquus was found in a recently rediscovered dig site in north Wiltshire that was first excavated during Victorian times. The excavation was lead by Dr. Phil Wilby, and was sponsored by the British Geological Survey and the Curry Fund.
B. antiquus was a belemnite, an extinct form of cephalopod closely related to modern squid and cuttlefish. Belemnites were abundant during the later part of the Mesozoic Era, but they went extinct at the end of the Cretaceous period. They resembled living squids, although they had ten hook-lined arms of equal length (no feeding tentacles) and an internal shell which protected the rear portions of the animial. This “guard” is usually the only part of a belemnite to become fossilized.