Cranial kinesis is the term for significant movement of skull bones relative to each other in addition to movement at the joint between the upper and lower jaw. Significant cranial kinesis is rare in mammals (the human skull shows no cranial kinesis at all). …
What is cranial kinesis in birds?
In birds cranial kinesis is characterised by the ability to move the upper bill or a part thereof relative to the cranium. It is generally accepted that the movement within bony parts of the beak occurs in bending zones, which are clearly recognisable as discrete areas of thin bone(Zusi, 1984).
Why do rabbits have cranial kinesis?
Early studies have suggested that cranial kinesis in rabbits functions as a shock-absorbing mechanism to dissipate kinetic energy during impacts associated with fast running.
Do snakes have a kinetic skull?
All reptiles of the super order Lepidosauria (lizards, snakes, and tuatara) have kinetic skulls, but they differ from the dinosaurs in that the joint on the floor of the skull occurs at the juncture of basisphenoid and pterygoid bones in lepidosaurians.
What is a braincase?
Medical Definition of braincase
: the part of the skull that encloses the brain — see cranium.
Where is maxillary?
The maxilla is the bone that forms your upper jaw. The right and left halves of the maxilla are irregularly shaped bones that fuse together in the middle of the skull, below the nose, in an area known as the intermaxillary suture.
What animals have quadrate Fusion?
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper part of the jaw joint.
What is the meaning of Rhynchokinesis?
noun. Zoology. A form of upper jaw mobility, found in some birds, in which the terminal part of the upper jaw may be raised or lowered independently of the rest of it by the bending of the nasal or premaxillary bones.
Do birds have jaws?
Birds also lack teeth or even a true jaw and instead have a beak, which is far more lightweight.
Do snakes feel pain?
Because of their slow metabolisms, snakes remain conscious and able to feel pain and fear long after they are decapitated.
Do any lizards have fangs?
Lizards bite with teeth rather than fangs. Venom enters the bite wound by dripping down grooves in the teeth rather than being injected through fangs, as it is with poisonous snakes. Lizards tend to hang on to their victims, making them hard to remove once they have bitten.
Do sharks have jaws?
Jaw: The jaws of sharks are not attached to their skull, instead moving separately with independent upper and lower jaws. This allows them to lift their head and thrust their mouth forward to bite its prey. While this varies among different species, most sharks have this ability to some degree.
What is another term for braincase?
cranium, braincase, brainpannoun. the part of the skull that encloses the brain. Synonyms: brainpan, cranium.
What is a large braincase?
Skull: Large; zygomata strong and arched; braincase well inflated. … Skull: Large; braincase well inflated; zygomatic arches strong and slightly appressed to skull.
What are the bones of braincase?
The brain case consists of eight bones. These include the paired parietal and temporal bones, plus the unpaired frontal, occipital, sphenoid, and ethmoid bones.
What is the Premaxilla?
Definition of premaxilla
: either of a pair of bones of the upper jaw of vertebrates between and in front of the maxillae.
What is maxillary nerve?
The maxillary nerve, or second division of the trigeminal, is a sensory nerve that crosses the pterygopalatine fossa, traverses the orbit in the infraorbital groove and canal in the floor of the orbit, and appears upon the face at the infraorbital foramen as the infraorbital nerve.
Is maxilla a irregular bone?
The irregular bones are: the vertebrae, sacrum, coccyx, temporal, sphenoid, ethmoid, zygomatic, maxilla, mandible, palatine, inferior nasal concha, and hyoid.
What does the word quadrate mean?
1 : being square or approximately square. 2 of a heraldic cross : expanded into a square at the junction of the arms — see cross illustration. 3 : of, relating to, or constituting a bony or cartilaginous element of each side of the skull to which the lower jaw is articulated in most vertebrates below mammals.
Does snake have skeleton?
As snakes are so flexible, it may be tempting to think that snakes have no bones. However, snakes do indeed have bones. … Snakes belong to the vertebrates, along with all other reptiles and amphibians, mammals, birds, and fish. All these animals have an inner skeleton.
What is the fate of quadrate bone in middle ear?
In mammals, the quadrate and articular bones have evolved into the incus and malleus bones in the middle ear.
Why is Rhynchokinesis important to birds?
We conclude that distal rhynchokinesis is a mechanism that could contribute to the flexible feeding behaviour of long-distance migratory shorebirds, enhancing small prey profitability and so improving foraging efficiency, and may have played a role in the evolutionary radiation of Scolopacidae (Charadrii).
Do birds fart?
And generally speaking, birds don’t fart; they lack the stomach bacteria that builds up gas in their intestines.
Why is a birds poop white?
The answer lies in the fact that birds, unlike mammals, don’t produce urine. Instead they excrete nitrogenous wastes in the form of uric acid, which emerges as a white paste. And uric acid doesn’t dissolve in water easily. Hence its ability to stick to your windshield like blobs of white plaster.
What bird can fly backwards?
The design of a hummingbird’s wings differs from most other types of birds. Hummingbirds have a unique ball and socket joint at the shoulder that allows the bird to rotate its wings 180 degrees in all directions.
Can a snake live if you cut it in half?
Yes, snakes die after being cut in half, beheaded, smashed flat, crushed flat or whatever. They are a bit simpler animals than mammals but basically what will kill a mammal will kill a snake. About the only thing you can cut off of a snake and have it live is the tail.
Can snakes feel love?
Some snake owners feel as though their snake recognises them and is more eager to be held by them than by other people. However, snakes don’t have the intellectual capacity to feel emotions such as affection.
Do iguanas have 3 eyes?
Iguanas have a so-called “third eye” on the top of their heads. Known as the parietal eye, it looks like a pale scale and can’t discern shapes or color—but does sense light and movement, helping iguanas anticipate predatory birds from above.
What happens if you get bit by a lizard?
Common symptoms include pain, swelling, and discoloration in the area around the bite as well as swollen lymph nodes. Weakness, sweating, thirst, headache, and ringing in the ears (tinnitus) may develop. In severe cases, blood pressure may fall.
What happens if a house lizard bites you?
Lizards tend to avoid confrontation. Bites are only inflicted when they are manipulated or when they are cornered and feel threatened. Lizard bites may be frightening but most do not cause serious health problems. The wall lizard or gecko, found in most homes, is not poisonous at all.
How do sharks sleep?
Some sharks such as the nurse shark have spiracles that force water across their gills allowing for stationary rest. Sharks do not sleep like humans do, but instead have active and restful periods.
How sharp are white teeth?
Triangular razor-sharp teeth
The great white shark is one of the world’s most notorious predators. But still, it would be nothing without its 300 serrated teeth. They’re designed to rip and grip through flesh, much like we use a knife and fork. And its jaw crunches down with almost two tonnes of force.
Do sharks have tongues?
Do sharks have tongues? Sharks have a tongue referred to as a basihyal. The basihyal is a small, thick piece of cartilage located on the floor of the mouth of sharks and other fishes. It appears to be useless for most sharks with the exception of the cookiecutter shark.
What is another name for the tailbone?
The coccyx is a triangular arrangement of bone that makes up the very bottom portion of the spine below the sacrum. It represents a vestigial tail, hence the common term tailbone.