-dinosaurs- - ☯✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨🚀*THE 2ND NATURE*🚀

-as of [26 MAY 2024]–

(‘dinosaurs’ are a diverse group of ‘reptiles’ of the clade ‘dinosauria’)

(they first appeared during the ‘tri-assic period’)

(between 243 – / – 233.23 million years ago)

(although the exact ‘origin’ + ‘timing’ of the ‘evolution’ of ‘dinosaurs’ is the ‘subject’ of ‘active research’)

“right on boys! dig even deeper!…”
‘no one’
(ever)

(they became the dominant terrestrial vertebrates after the ‘tri-assic (/ ‘jur-assic’) extinction event ‘201 million years ago’)

(their dominance continued through the ‘jurassic’ + ‘cretaceous’ periods)

(the ‘fossil record’ demonstrates that ‘birds’ are ‘modern feathered dinosaurs’, having evolved from earlier ‘theropods’ during the ‘late jurassic period’)

As such, birds were the only dinosaur lineage to survive the Cretaceous–Paleogene extinction event 66 million years ago.

Dinosaurs can therefore be divided into avian dinosaurs, or birds; and non-avian dinosaurs, which are all dinosaurs other than birds.

This article deals primarily with non-avian dinosaurs.

Dinosaurs are a varied group of animals from taxonomic, morphological and ecological standpoints.

Birds, at over 10,000 living species, are the most diverse group of vertebrates besides perciform fish.

Using fossil evidence, paleontologists have identified over 500 distinct genera and more than 1,000 different species of non-avian dinosaurs.

Dinosaurs are represented on every continent by both extant species (birds) and fossil remains.

Through the first half of the 20th century, before birds were recognized to be dinosaurs, most of the scientific community believed dinosaurs to have been sluggish and cold-blooded.

Most research conducted since the 1970s, however, has indicated that all dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction.

Some were herbivorous, others carnivorous.

Evidence suggests that all dinosaurs were ‘egg-laying’; and ‘nest-building’ was a trait shared by many dinosaurs, both avian and non-avian.

While dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, and some were able to shift between these stances.

Elaborate display structures such as horns or crests are common to all dinosaur groups, and some extinct groups developed skeletal modifications such as bony armor and spines.

While the dinosaurs’ modern-day surviving avian lineage (birds) are generally small due to the constraints of flight, many prehistoric dinosaurs (non-avian and avian) were large-bodied—the largest sauropod dinosaurs are estimated to have reached lengths of 39.7 meters (130 feet) and heights of 18 meters (59 feet) and were the largest land animals of all time.

Still, the idea that non-avian dinosaurs were uniformly gigantic is a misconception based in part on ‘preservation bias’, as — ‘large’ / ‘sturdy’ –bones are more likely to last until they are ‘fossilized’)

(many dinosaurs were quite small…)

*xixianykus was only about 50 cm (20 in) long*

(since the first ‘dinosaur fossils’ were recognized in the ‘early 1800s’, ‘mounted fossil dinosaur skeletons’ have been major attractions at ‘museums’ around the world)

(‘dinosaurs’ have become an enduring part of ‘world culture’)

(the large sizes of some ‘dinosaur groups’ (as well as their seemingly ‘monstrous’ + ‘fantastic’ nature), have ensured dinosaurs’ regular appearance in ‘best-selling — books / films’ –, such as Jurassic Park.

(‘persistent public enthusiasm’ for the animals has resulted in significant ‘funding’ for ‘dinosaur science’)

(major discoveries in ‘dinosaur science’ are regularly covered by the ‘media’)

*the final dinosaur died ~65 million years ago*

(all that remain of them are the ‘birds’)
(“t-rex had ‘feathers'”…)
(“primordial cross-dressers”)

‘allosaurus’