Upper Coniacian Left: A Squalicorax kaupi tooth in lingual far left and labial views. Their pectoral and pelvic fins consist of joints that resemble tetrapod limbs. Some of the largest bony fish that ever swam were in the Western Interior Sea during the Cretaceous Period and have left abundant remains. The remains of plethodids are a fairly common in the Smoky Hill Chalk. Since the original discovery, another set of fragmentary remains has been collected J. Salts are still diffused into their body but are excreted over the gills, within the urine, and by the rectal gland that extracts salt from the blood.
This is only the second known specimen of a ratfish from the Smoky Hill Chalk. Exoskeleton Bony Fish:The exoskeleton of bony fish is made up of thin bony plates known as cycloids. Journal of Vertebrate Paleontology 31 Suppment to 3 :103. Neuromasts help to sense water pressure and vibrations. Although several new species have been found inside clam shells, most have not yet been described. Sharks and their relatives have a skeleton made of cartilage, the same lightweight, flexible connective tissue found around our joints and the flexible part of our nose.
Note the forward facing teeth in both the upper and lower jaws. Their liver is very large and filled with oil, because oil is lighter than water. Teeth are small, equal-sized and blade shaped. They are also known as elasmobranchii. Life History Sharks have developed a life history strategy that requires slow growth to a relatively large size.
For some reason, Cretoxyrhina mantelli seems to reach it's largest size and greatest abundance in the lower one third of the chalk Late Coniacian , and then, judging from the size of the shed teeth that are found, becomes rarer and smaller in the upper chalk. Journal of Vertebrate Paleontology 28 3 :650-658. This species has a triple row of teeth on the lower jaws and premaxillae, and no teeth on the maxillae. The partial lower jaw is 20. Although of fish, they are not extinct as once thought and are still present in the Indian Ocean near Madagascar, and in the East Indies.
Many times, however, of the leftovers from a larger predator's meal. Although the jaw plates see below appear to be bone, they are actually composed of calcified cartilage. It was discovered in the Smoky Hill Chalk of western Kansas. These teeth were shed and replaced periodically as the fish grew larger and the length of the jaws increased. These fish reached a length of 5 or 6 feet and may have fed on plankton or other small food material filtered from the water around them, but more likely ate smaller fish. Top row: Two palatine bones with partial fangs; Bottom row: two lower jaws. Left: A badly weathered P.
Cartilaginous Fish:Cartilaginous fish can be exclusively found in marine water. Superorder Neoteleostei Order Alepisauriformes Cimolichthys was a common, small to medium size predatory fish. They share similarities as well as differences. The jaw plate is approximately 10 inches wide by 18 inches in length and includes more than 500 teeth. This leads to some sharks losing tens of thousands of teeth in their lifetime, as opposed to the few dozen humans lose. Left: Ptychodus anonymus teeth, from the medial row. Endoskeleton Bony Fish:Bony fish has an endoskeleton made up of bones.
The specimen was subsequently described as a new species A. There is no connection between their upper jaw and skull, so that they can move it independently. Bony fish on the fast track have the ability to replace itself in a population quickly but all of the characteristics listed above mean sharks take a lot longer. See upper left of Plate 26 Age is Santonian. Other specimens have been collected in Gove County, but preservation of the skeleton, especially the skull, is usually poor due to the small size. Paläontologische Zeitschrift 79 2 : 241-261.
It grew to lengths of 8 to 10 feet and was a predator on smaller fish see Everhart, et. Isolated teeth are frequently collected in the Smoky Hill Chalk. Much of their diet is made up of live prey, although they eat corpses when available. They became extinct during the Santonian, about 85 million years ago. Right: Detail of a that I found in Gove County in 1990. From the large size of this scale, it is most likely from a Xiphactinus or an Ichthyodectes. They were probably very similar in behavior to the modern Great White Shark, but were not closely related.
A six foot long fish with a big mouth is quite capable of taking smaller fish and squid, with or without an array of impressive teeth. They are found in shallow tropical and subtropical waters, where they swim along the reefs. There are a few differences between cartilaginous fish and bony fish that are pretty apparent. All cartilaginous fish are predators, although the phytoplankton also ingest phytoplankton. I suppose my specimen was old at the time of its death, and bony matter had been deposited in the cartilage. Most of the skeleton was bone and preserves well.