What is the chondrocranium of a shark?
The chondrocranium is the large single element of the head skeleton (Figure 3.2). It surrounds and provides support for the brain and sense organs. The scoop-like rostrum projects anteriorly and contains the precerebral cavity.
What does Meckels cartilage give rise to?
Meckel’s cartilage is comprised of three distinct regions. The anterior and posterior regions undergo endochondral ossification and contribute to mandibular development, and to formation of the malleus and incus (ear bones) respectively. The middle region degenerates and gives rise to the sphenomandibular ligament.
What is the meaning of Palatoquadrate?
Definition of palatoquadrate : of, relating to, or replacing the palatine and quadrate bones especially : constituting a series of bones or a continuous cartilaginous rod that forms part of the upper jaw or roof of the mouth of most vertebrates other than mammals.
Do all vertebrates have an endoskeleton?
All vertebrates have an endoskeleton. However invertebrates can be divided again between those with an exoskeleton and those with a hydrostatic skeleton. Animals with endoskeletons have skeletons on the inside of their bodies. As the animal grows so does their skeleton.
Where did the chondrocranium come from?
The more rostral portion of the chondrocranium that lie anterior to the notochord constitutes the prechordal chondrocranium, and is derived primarily from neural crest-derived mesenchyme.
What is Meckels cartilage?
Meckel (1781–1833), is hyaline cartilage formed in the mandibular process of the first branchial arch of vertebrate embryos. An intermediate portion of Meckel’s cartilage is absorbed by multinucleated cells and disappears during the following developmental stages in mammals.
Do sharks have a Splanchnocranium?
The shark has a chondrocranium and splanchnocranium but no dermatocranium. Its skeleton is also cartilaginous as opposed to being made of bone.
What is a endoskeleton called?
An endoskeleton (From Greek ἔνδον, éndon = “within”, “inner” + σκελετός, skeletos = “skeleton”) is an internal support structure of an animal, composed of mineralized tissue.