Latest Mammal Stories

Discovery of an evolutionary trait from our earliest ancestors could provide insight into the early development of human embryosUsing the model organism Ciona intestinalis, commonly known as the sea squirt, researchers at the University of California, Berkeley, have uncovered the origins of the second heart field in vertebrates.Sea squirts are bag-like gelatinous creatures whose full genome has been sequenced--one that shares 80 percent of its genes with humans. Though its body is clearly...

Mammals with larger brains in relation to body size tend to live longer. This is the conclusion reached by researchers at the Centre for Ecological Research and Forestry Applications (CREAF), affiliated to Universitat Autònoma de Barcelona, after having analyzed almost 500 mammal species and obtaining new data on the relation between brain size and lifespan.The brain size of some mammals is larger than expected for their body size. This is the case of large primates, such as chimpanzees...

Changes in the marine ecosystem are effecting reproduction in harbor seals (Phoca vitulina) causing them to give birth to their pups much earlier than usual, according to a recent study. The study found that the mammals are birthing their pups 25 days earlier compared to 35 years ago. Scientists believe that removal of large fish species by the fishing industry was allowing populations of smaller species to thrive. These smaller species are favored by the seals. "We report on a continual...

In a novel mathematical model that reproduces sleep patterns for multiple species, an international team of researchers has demonstrated that the neural circuitry that controls the sleep/wake cycle in humans may also control the sleep patterns of 17 different mammalian species. These findings, reported by researchers from Brigham and Women's Hospital (BWH), the University of Sydney, and the Center for Integrated Research and Understanding of Sleep (Camperdown, Australia), suggest that...

Paleontologists have discovered the oldest mammalian tooth marks yet on the bones of ancient animals, including several large dinosaurs. They report their findings in a paper published online June 16 in the journal Paleontology.Nicholas Longrich of Yale University and Michael J. Ryan of the Cleveland Museum of Natural History came across several of the bones while studying the collections of the University of Alberta Laboratory for Vertebrate Palaeontology and the Royal Tyrrell Museum of...

Your mother was right: Fish really is "brain food." And it seems that even pre-humans living as far back as 2 million years ago somehow knew it.A team of researchers that included Johns Hopkins University geologist Naomi Levin has found that early hominids living in what is now northern Kenya ate a wider variety of foods than previously thought, including fish and aquatic animals such as turtles and crocodiles. Rich in protein and nutrients, these foods may have played a key role in...

Could help scientists track paleoclimate, determine whether dinosaurs and other species were warm- or cold-bloodedWas Tyrannosaurus rex cold-blooded? Did birds regulate their body temperatures before or after they began to grow feathers? Why would evolution favor warm-bloodedness when it has such a high energy cost?Questions like these"”about when, why, and how vertebrates stopped relying on external factors to regulate their body temperatures and began heating themselves internally"”have...

New fossil material redefines Azendohsaurus as a peculiar early reptileAzendohsaurus just shed its dinosaur affiliation. A careful new analysis of A. madagaskarensis"”this time based on the entire skull rather than on just teeth and jaws"”aligns this 230-million-year-old animal with a different and very early branch on the reptile evolutionary tree. Many aspects of Azendohsaurus are far more primitive than previously assumed, which in turn means that its plant-eating adaptations, similar...

The squirrels littering your lawn with acorns as they bound overhead will live to plague your yard longer than the ones that aerate it with their burrows, according to a University of Illinois study.Scientists know from previous studies that flying birds and bats live longer than earthbound animals of the same size. Milena Shattuck and Scott Williams, doctoral candidates in anthropology, decided to take a closer look at the relationship between habitat and lifespan in mammals, comparing...

Scientists have discovered that air flows in one direction as it loops through the lungs of alligators, just as it does in birds.The results, published in this week's issue of the journal Science, suggest that this breathing method may have helped dinosaurs' ancestors dominate Earth after the planet's worst mass extinction 251 million years ago.Before and until about 20 million years after the extinction--called "the Great Dying" or the Permian-Triassic extinction--mammal-like...