| Megalosauridae | |
|---|---|
| |
| Megalosaurus bucklandii | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Sauropsida |
| clade: | Dinosauria |
| Suborder: | Theropoda |
| Family: | †Megalosauridae Huxley, 1869 |
| Type species | |
| †Megalosaurus bucklandii Mantell, 1827 | |
| Synonyms | |
| |
Megalosauridae (Huxley, 1869) was a family of megalosauroid theropod dinosaurs that lived from the Middle Jurassic to the Mid-Cretaceous. Its name derives from the infamous and the first dinosaur to be scientifically studied, Megalosaurus. Some notable member species include Megalosaurus and Torvosaurus.
A mystery in a lost world[]
Megalosauridae is as mysterious as the dinosaur it was named after, in fact, it has been commonly used as a "wastebasket" group, with any unidentified species instantly classified as a Megalosauridae. This use was not liked by many scientists, which is why in 1985, James A. Jensen coined the term, Torvosauridae, though under official rules, the name change is not allowed.
Description[]
Body Size[]
Like other tetanurans, Megalosaurids are carnivores theropods characterized by large size and bidedalism. Specifically, Megalosaurids exhibit especially giant size, with some members of the family weighing more than one tonne. Over time, there is evidence of size increase within the family. Basal Megalosaurids from the early Jurassic had smaller body size than those appearing in the late Middle Jurassic. Due to this size increase over time, Megalsaurdea appear to follow a size increase pattern similar to that of other giant sized theropods like Spinosauridae. This pattern follows Cope's Rule, the postulation by palentologist Edward Cope about evolutionary increase in body size.
Dental Morphology[]
Dental finding are frequently used to differentiate between various theropods and to further inform cladistic phylogeny. Tooth morphology and dental evolutionary markers are prone to homoplsay and disappear or reappear throughout history. however, Megalosaurids have several specific denture conditions that differentiate them from other basal theropods. One dental condition present in Megalosauridea is multiple enamel wrinkles near the carinae, the sharp edge or serration row of the tooth. Ornamented teeth and a well-marked enamel surface also characterize basal Megalosaurids. The ornamentation and well-marked surface appears in early Megalosaurids. But disappears in derived Megalosaurids, suggesting that the condition was lost over time as Megalosaurids grew in size.