Where are Exogyra found?
Distribution. Fossils of Exogyra have been found in: Jurassic. Afghanistan, Chile, China, Eritrea, Ethiopia, France, Germany, India, Kenya, Poland, Portugal, Somalia, Spain, Tanzania, the United Kingdom, and Yemen.
Who discovered Exogyra?
Böse proposed the existence of two distinct species of Exogyra plexa-like oysters in strata below the Kiamichi Formation .
Is Exogyra an index fossil?
One of the index fossil shown in the fossil range graph is Exogyra, a type of oyster.
What symmetry is Exogyra?
Found in shallow marine deposits from the Jurassic and Cretaceous periods, the genus exogyra is an asymmetrical bivalve. The left valve is shaped almost like a cup and was used to cement the mollusk, while the right valve was much flatter and smaller.
When did Exogyra go extinct?
200 million to 65.5 million years ago
Exogyra, extinct molluscan genus common in shallow-water marine deposits of the Jurassic and Cretaceous periods (from about 200 million to 65.5 million years ago).
What type of symmetry does Mucrospirifer have?
Genus: Mucrospirifer; Species: thedfordensis. The opposite side of the shell has a protruding ridge on it. The shell is not symmetrical because one side protrudes in and the other side protrudes out.
Why does Alabama have more dinosaur fossils than most Eastern states?
Most of present-day Alabama was covered in a shallow sea for millions of years, and so most of the fossils found in the state are of marine creatures, including giant mosasaurs and ancient oysters.
What are the two 2 correct definitions of an index fossil?
Index fossil, any animal or plant preserved in the rock record of the Earth that is characteristic of a particular span of geologic time or environment. A useful index fossil must be distinctive or easily recognizable, abundant, and have a wide geographic distribution and a short range through time.
What are the two 2 correct example of trace fossils?
Tracks, burrows, eggshells, nests, tooth marks, gastroliths (gizzard stones), and coprolites (fossil feces) are examples of trace fossils or ichnofossils. Trace fossils represent activities that occurred while the animal was alive.
What type of symmetry does a Mucrospirifer have?
Mucrospirifer; Species: thedfordensis. The opposite side of the shell has a protruding ridge on it. The shell is not symmetrical because one side protrudes in and the other side protrudes out.
What was in the Cretaceous period?
Is the Mucrospirifer extinct?
Mucrospirifer, genus of extinct brachiopods (lamp shells) found as fossils in Middle and Upper Devonian marine rocks (the Devonian Period began 416 million years ago and lasted about 57 million years).