Mesozoic Marine Revolution
Encyclopedia
The Mesozoic marine revolution (MMR) was a fundamental restructuring of marine
ecosystems during the Mesozoic
era
, particularly in the Jurassic and Cretaceous, caused by increased predation
pressure.
The term was coined by Geerat J. Vermeij
(1977) based on the earlier work of Steven M. Stanley
(1974).
The MMR was not the first bout of increased predation pressure; this also occurred around the end of the Ordovician
.
Some taxa began to diversify before the MMR, notably the crinoids, who were perhaps responding to increased benthic predation pressure.
s, and endobyssate bivalves.
Weakly armoured gastropods also disappeared, while more heavily armoured taxa diversified.
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
ecosystems during the Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
era
Era
An era is a commonly used word for long period of time. When used in science, for example geology, eras denote clearly defined periods of time of arbitrary but well defined length, such as for example the Mesozoic era from 252 Ma–66 Ma, delimited by a start event and an end event. When used in...
, particularly in the Jurassic and Cretaceous, caused by increased predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
pressure.
The term was coined by Geerat J. Vermeij
Geerat J. Vermeij
Dr. Geerat J. Vermeij, born in the Netherlands, is a professor of geology at the University of California at Davis. Blind from the age of three, he graduated from Princeton University in 1968 and received his Ph.D. in biology and geology from Yale University in 1971.An evolutionary biologist and...
(1977) based on the earlier work of Steven M. Stanley
Steven M. Stanley
Steven M. Stanley is an American paleontologist and evolutionary biologist at the University of Hawaii at Manoa. He is best known for his empirical research documenting the evolutionary process of punctuated equilibrium in the fossil record.Stanley received his Ph.D. from Yale University in 1968...
(1974).
The MMR was not the first bout of increased predation pressure; this also occurred around the end of the Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
.
Some taxa began to diversify before the MMR, notably the crinoids, who were perhaps responding to increased benthic predation pressure.
Casualties
Organisms which went into decline include stalked crinoids, articulate brachiopodBrachiopod
Brachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...
s, and endobyssate bivalves.
Weakly armoured gastropods also disappeared, while more heavily armoured taxa diversified.