Search results
Results from the WOW.Com Content Network
Ammolite comes from the fossil shells of the Upper Cretaceous disk-shaped ammonites Placenticeras meeki and Placenticeras intercalare, and (to a lesser degree) the cylindrical baculite, Baculites compressus. Ammonites were cephalopods, that thrived in tropical seas until becoming extinct along with the dinosaurs at the end of the Mesozoic era.
Fossils. Dorling, Kindersley Limited, London, 2002. A Broad Brush History of the Cephalopoda by Dr. Neale Monks, from The Cephalopod Page. Ammonite maturity, pathology and old age By Dr. Neale Monks, from The Cephalopod Page. Essay about the life span of Ammonites. Cretaceous Fossils Taxonomic Index for Order Ammonoitida
The Mazon Creek fossil beds are a conservation lagerstätte found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions , formed approximately 309 million years ago in the mid- Pennsylvanian epoch of the Carboniferous period.
This list of ammonites is a comprehensive listing of genera that are included in the subclass †Ammonoidea, excluding purely vernacular terms. The list includes genera that are commonly accepted as valid, as well as those that may be invalid or doubtful ( nomina dubia ), or were not formally published ( nomina nuda ), as well as junior ...
The line where each septum meets the outer shell is called the suture or suture line. Like other true ammonites, Baculites have intricate suture patterns on their shells that can be used to identify different species. A fossil cast of the shell of a Baculites grandis on display at the North American Museum of Ancient Life in Lehi, Utah.
Their shells had ornate ribs whose function is unknown, although some scientists have speculated that these ribs helped strengthen the animals' shells to allow them to live at greater depths where the water pressure is higher.
W. A. Cobban and Hook, S. C. 1983 Mid-Cretaceous (Turonian) ammonite fauna from Fence Lake area of west-central New Mexico. Memoir 41, New Mexico Bureau of Mines&Mineral Resources, Socorro NM. W. A. Cobban and Hook, S. C. 1979, Collignoniceras woollgari wooollgari (Mantell) ammonite fauna from Upper Cretaceous of Western Interior, United States.
These ammonites lived in the Jurassic from Sinemurian to Toarcian [2] (age range: 196.5 to 182.0 million years ago). Fossils of this genus can be found in Argentina, Austria, Canada, Chile, China, France, Germany, Hungary, Italy, Morocco, Portugal, Slovakia, Spain, Tunisia, Turkey and United States.