Search results
Apr 16, 2009 · Cetaceans (whales, dolphins, and porpoises) are an order of mammals that originated about 50 million years ago in the Eocene epoch. Even though all modern cetaceans are obligate aquatic mammals, early cetaceans were amphibious, and their ancestors were terrestrial artiodactyls, similar to small deer.
- J. G. M. Thewissen, Lisa Noelle Cooper, Lisa Noelle Cooper, John C. George, Sunil Bajpai
- 2009
May 21, 2007 · The fossil record demonstrates that mammals re-entered the marine realm on at least seven separate occasions. Five of these clades are still extant, whereas two are extinct. This review presents a brief introduction to the phylogeny of each group of marine mammals, based on the latest studies using both morphological and molecular data.
- Mark D. Uhen
- 144
- 2007
- 21 May 2007
Meet Pakicetus, a goat-sized, four-legged creature that scientists recognise as one of the first cetaceans (the group of marine animals that includes dolphins and whales). How Pakicetus ' descendants evolved into whales is one of the most intriguing evolutionary journeys known to science.
Sep 24, 2014 · If I understand evolutionary biology correctly, mammals first evolved on land as small, rodent-like creatures, in a time when reptiles were dominant on land. Eventually, they diversified into the species we know today.
Apr 16, 2015 · But now, for the first time, a team of researchers has created an overview that not only provides insight into evolution, but may also help more accurately assess humans’ impact on the planet.
A review of the broad outlines of what we know about the evolution of marine mammals from their fossil record, and then a focus on three discrete case studies that highlight important ecological transitions and evolutionary transformations that have occurred over the past 50 million years.
People also ask
How long did it take for marine mammals to evolve?
Do marine mammals have evolutionary histories?
When did mammalian evolution start?
How many times did mammals re-enter the marine realm?
The history of marine biology can be traced as far back as 1200 BC when the Phoenicians and the Greeks began ocean voyages using celestial navigation. Phoenicians and Greeks were some of the first known explorers to leave their local communities bordering the Mediterranean Sea.
