This shot of the dorsal neck of a developing mouse embryo visually shows the process of skeletal growth found in all bony vertebrates. The widespread blue stain (Alcian blue) reveals the extensive cartilaginous blueprint for the growing skeleton, which extends by the division of chondrocytes (cartilage-producing cells) guided by signalling molecules across the embryo. The…
Tag: evolution
Rock-climbing cavefish ‘walks’ like a salamander
One of our interests at the RVC is examining the early history of tetrapods (four-legged vertebrates) and how their ancestors made the transition from water to land. Some studies have examined species of living fishes that can move on land, such as mudskippers and lungfish, but although they are able to make do using their…
April fool! This ‘snail shell’ isn’t quite what it seems…
When is a snail not a snail? What if it’s something totally, completely different? This mollusc-like shell was described as a new species of trochid in 1903, but in fact it comes from an entire different phylum (one of the highest levels of distinction between animals). Any ideas what it might be instead? … It’s an anemone!…
#ThrowbackThursday: Reconstructions show that human brains may have evolved more recently than we thought
The human brain may have evolved much faster and more recently than previously thought, researchers suggest from reconstruction of hominid skulls. By scanning the skull of Australopithecus sediba, one of the earliest complete hominid skeletons, scientists could reconstruct the shape and size of the brain from an endocast of the cranium. Essentially, this means they could use the…
Rattlesnake strikes are far more sophisticated than a simple ‘spring’ release
More than half of a rattlesnake’s body may be involved in striking behaviour, particularly where the strike is defensive, and the anterior third of body length is usually active when hunting. The remainder of the body ‘anchors’ the snake to a solid base position. Tracking the kinematics of a single strike reveals that different segments of…
#fossilfriday: Beautifully-preserved amber lizards reveal chameleons’ evolution in ancient Myanmar.
A researcher working in the American Museum of Natural History, New York, has confirmed the age of the world’s oldest known fossil chameleon in part of a bumper find of fossilised lizards. In an almost Jurassic-Park style story, twelve of these ancient reptiles were encased in amber (sap from a coniferous tree) in what is…
Ole’ blue eyes: scallops and clams have unique ‘mirrored’ eyes
It may seem alien, but think about this the next time you enjoy a scallop or a clam: they might be looking back at you. Some species have tens of tiny eyes which line the edges of their characteristic shells. Unlike almost all other adult bivalves, scallops and clams can grow eyes which use a unique…
Photographer captures turtle skeleton and discovers a clutch of eggs
Ted Kinsman, professor of photographic sciences at the Rochester Institute of Technology, found this unfortunate expired snapping turtle at the roadside and made it the subject of his next project. What he didn’t expect was to discover a clutch of eggs within, revealed by X-ray. Turtles may have carry up to 30 fertilised eggs from…
#fossilfriday: Head of Romundina , a 415 million year-old fish, gives glimpse into jaw evolution.
One of the most significant evolutionary innovations in early vertebrates was the jaw. Jawless fishes such as lampreys and hagfish have rows of teeth around the mouth opening which are used to rasp at prey, whereas most modern jawed fish and other vertebrates (collectively Gnathostomes) have an upper and lower jaw, with the lower jaw usually…
Sections through tough wombat femur show possible adaptation to digging.
Wombats are marsupial mammals that are only found in Australia. They are fossorial and dig out extensive networks of burrows. Wombats have a variety of adaptations to this lifestyle, which is energetically demanding and unusual in marsupials, including a unique backwards-facing pouch to prevent young being smothered with dirt while digging. This lovely section, which represents a…
In focus: New genetic method proves the importance of wing geometry in ‘superflies’.
What defines the biomechanical performance of an animal? Dr Robert Ray (Francis Crick Institute), in collaboration with Dr Richard Bomphrey’s group at the Royal Veterinary College have just published their findings that by altering the production of just one protein they can change – and even improve – flight agility in fruit flies. This ground-breaking…
Glyptodonts may have evolved neck protection in response to new sabre-toothed predators
Glyptodonts are an extinct group of large mammals which were reasonably common across South (and later, Central) America during the Pleistocene era. These large herbivores resembled ankylosaurs and armadillos, to the latter of which they are close relatives. They could be the size of a small car, with short legs and a fairly squat posture….
Anatomy To You 