Sentences with phrase «with placental mammals»

They have assumed that marsupials could prosper only on a backwater continent like Australia, where they were insulated from competition with placental mammals.

Not exact matches

The marsupials (mammals with pouches, e.g. kangaroos) and eutherians (placental mammals that give birth to well - developed young, e.g. humans) both give birth to live young.

A few that pop to mind are the Coconino Sandstone, the meandering / lateral channels in the Grand Canyon, the progressive order of the fossil record (complete with a pre-hominid through hominid progression), forms which bear features bridging the specially - created kinds (i.e. fish with tetrapod features, reptiles with mammalian features, reptiles with avian features, etc), the presence of anomalous morphological / genetic features (e.g. the recurrent laryngeal nerve, male nip - ples, the presence of a defunct gene for egg - yolk production in our own placental mammal genomes), etc, etc..

A term most applicable to placental species, multiple births occur in most kinds of mammals, with varying frequencies.

To figure out how chromosomes of placental mammals have changed over time, researchers need to know what those early eutherians started with.

But he quibbled with the conclusion, noting that previous studies indicated that some placental mammals were present in the late Cretaceous.

When geneticists compare DNA sequences of the world's placental mammals, the results cluster into a family tree with four major groups.

Our finding is broadly consistent with recent estimates for placental mammals -LSB-(100), but see SM12 (101)-RSB- and thus supports the hypothesis that the K - Pg transition was associated with a rapid species radiation caused by a release of ecological niches following the environmental destruction and species extinctions linked to an asteroid impact (2, 4, 5, 102).

Small, furry and with a penchant for insects, the greatest grandparent of all modern placental mammals lived after the dinosaurs were wiped out

Meet our last common mammalian ancestor Small, furry and with a penchant for insects, the greatest grandparent of all modern placental mammals lived after the dinosaurs were wiped out.

But Stephen O'Brien, an evolutionary biologist with the National Cancer Institute in Frederick, Maryland, is not convinced the work tells the true story of placental mammals.

By comparing 400 morphological features, such as the shapes and numbers of teeth, in the new fossil with those in 68 other specimens, the researchers have now placed the 73 - million - year - old creature in the Eutherian evolutionary tree, an umbrella group that includes placental mammals.

Along with post-Cretaceous marsupials identified in recent years from South America, Antarctica, Africa, and Australia, as well as a Late Cretaceous placental mammal from India reported in 1994, the new molar suggests that southern landmasses have an unexpected story to tell.

More recent genetic analysis — not yet universally accepted — places bats in the superorder Laurasiatheria, with a diverse bunch of other placental mammals including whales, dogs and giraffes.

The Stanford group compared the platypus genome with those of fish, frogs, birds, marsupials and placental mammals.

A group of researchers has re-created with remarkable accuracy part of the genome of the common ancestor of almost all placental mammals, a small shrew - like creature that prowled the forests of what...

These results are consistent with the hypothesis that the Cretaceous - Paleogene mass extinction of non-avian dinosaurs played an important role in the diversification of placental mammals.

Just ask the marsupials in South America and Africa that had to deal with those selfish placental mammals.