Romer's gap

Romer's Gap is an example of a gap in the fossil record. It is named after paleontologist Dr. Alfred Romer. The fossil record is used in the study of evolution. A fossil record gap is a period from which excavators have found very few fossils.

Romer's Gap runs from approximately 360-340 million years ago. Before the gap's time no amphibian fossils have been found. The oldest amphibian fossil found dates back to approximately 340 million years ago. The first fish fossil found before that time dates back to about 360 million years ago. This period of time from 360-340 million years ago shows very few fossils that have fish-like or amphibian-like characteristics (Airhart, 2004).

Scientists are not certain why there are so few fossils from this time period. Some suggest the climate was not suitable for fossils to form. Others think there may have been differences in the soil minerals which also would have not allowed fossil formation. Also, excavators may not have dug in the right places. Perhaps erosion or shifts in the earth’s plates caused these fossils to be displaced from the chronological layers of rock (Airhart, 2004). Among the few sites where vertebrate fossils have been found to help fill in the gap, which is simply a gap in current knowledge, is East Kirkton Quarry, in Bathgate, Scotland, a long-known fossil site that was revisited by Stanley P. Wood in 1984 and has since been revealing a number of early tetrapods; [Clack, Jennifer A. (2002), "Gaining Ground: the Origin and Evolution of Tetrapods". Indiana Univ. Press.] "literally dozens of tetrapods came rolling out: "Balanerpeton" (a temnospondyl), "Sivanerpeton" and "Eldeceeon" (basal anthracosaurs), all in multiple copies, and one spectacular proto-amniote, "Westlothiana", "Paleos" Project reports. [ [http://www.palaeos.com/Paleozoic/Paleozoic2.html Paleos Proterozoic: Proterozoic sites] ]

Notes

References

*Airhart, M. (2004). Romer’s Gap. Retrieved March 1, 2005, from Earth & Sky. Copyright Byrd & Block Communications Inc.: http://www.earthsky.org/shows/