What is the fossil record? The fossil record is a history of life preserved through fossilized remains or imprints of living organisms, usually found in sedimentary rock.
Although it is incomplete, the fossil record gives us an overview of the different types of organisms, and their placement within the earth can give us an idea of various things such as date of life, geological conditions and environments, migration patterns and keys to evolution itself.
In the Mesozoic Era there is a wide variety of fossils which have been found, some exceptionally preserved. Most people are quite familiar with the reconstructed Dinosaurs which can be found in museums all over the world and are an extremely unique insight into that Mesozoic environment.
In the marine setting, there is some examples of life preserved that are equally as impressive.
Just recently in Majiashan, Anhui, China, 80 new Ichthyosaur remains were located in a series of excavations. One of the individuals that was discovered, of the genera Chaohusaurus aged approximately 248 ma old, was discovered to have been preserved during the act of giving birth to its young.
This astonishing find may well readjust the way we think about the environment where these reptiles gave birth, due to the way it was preserved. The baby Ichthyosaur was found to be exiting the parent in a head first direction which indicates a land based birth rather than a sea based one.
The age of the embryos found are older than any found previous to that by approx 10 million years which may mean that live birth evolved much sooner than was thought. This type of rare and exciting find can clear up big concepts within a species and provides missing links of the overall picture that the fossil record paints.
Chaohusaurus, Majiashan, Anhui, China
Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic Embryonic Fossils
References http://novataxa.blogspot.ie/2014/02/chaohusaurus-terrestrial-viviparity.htmlSystematics and the Fossil Record: Documenting Evolutionary Patterns - Andrew B. Smith 2.Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic- Embryonic Fossils
Ryosuke Motani,Da-yong Jiang mail,Andrea Tintori,Olivier Rieppel,Guan-bao Chen
Dinosaurs,Spitfires and Seadragons- Christopher McGowan
Mesozoic Marine Reptiles 