Lone Star Dinosaurs, Louis Jacobs, c. 1995

Lone Star (Texas) Dinosaurs, Louis Jacobs, original artwork by Karen Carr, c. 1995.

I'm going to have to go back and re-look at The Mistaken Extinction but I believe the light bulb went on back in 1995 when it dawned on paleontologists that dinosaurs never went extinct; they live on as sparrows.

It will be interesting to read Louis Jacobs' thoughts at this time about birds and dinosaurs. He would have been writing just about that time (1995).

Note: everything below was "true" in 1995 and before. 

Chapter 2: The Original Homestead: Texas

Three major locations for Texas dinosaur hunters:

• oldest dinosaurs: the panhandle
• the most recent dinosaurs: Big Bend
• in-between: central Texas, i.e., Fort Worth, and more specifically, 60 miles southwest of Ft Worth

The eras:

• Paleozoic Era: era of fishes
• Mesozoic Era: era of reptiles
• Cenozoic Era: age of mammals

Mesozoic Era:

• Triassic: earliest dinosaurs
• Jurassic: the entire zoo
• Cretaceous: doomsday for the dinosaurs; but what a great time to have been alive -- until ...

Pangea: the entire land mass on earth was reachable by railroad -- from the late Paleozoic to the early Mesozoic (Triassic).

Gondwana was the largest piece of Pangea. In the Carboniferous period of the Paleozoic, Gondwana, the larger piece, joined with Laurussia to form Pangea. 

Gondwana made up about two thirds of today's continental area, including South America, Africa, Antarctica, Australia, and the Indian Subcontinent.

The rest, I suppose, became North America, the Arctic, and Brooklyn.

Dinosaurs could walk everywhere; the rest of us could have taken bullet trains.

Argentina: where the most-precisely dated early dinosaurs are found -- 230 million years ago
Texas: dinosaurs didn't show up until 10 million years later; 220 million years ago; it must have been a long, slow slog from Argentina to Texas

Some names, from Argentina:

• oldest well-dated: Eorapator lunensis and Herrerasaurus ishigualastensis; contemporaries; both are carnivorous theropod saurischians.
• same location; earliest known ornithischian: Pisanosaurus mertii

From this park in Argentina, we know that the major dinosaur division (ornith- vs saur-) occurred very, very early in dinosaur evolution. Some fossils may have been dinosaurs before the division but too early to tell exactly what they were.

The Argentina dinosaurs are very, very early, but not known for sure where the "cradle" of dinosaurs exist. See New Scientist, 2017. 

Because both new branches include carnivores and herbivores, Baron’s team concludes that the common ancestor of all dinosaurs may have been omnivorous. The results also suggest that the cradle of dinosaur evolution may not have been South America, as has long been accepted. It could instead have been in the northern hemisphere since fossils of the oldest members of the new branches are found there. 

The article doesn't say more; perhaps the video did but I did not watch the video. But if the earliest were in northern hemisphere are we talking Texas or North Dakota?

The Nature article in 2017 has more information but again fails to mention more specifically than "North America." By 2017, paleontologists had stretched the earliest dinosaurs back to 247 million years ago.

Theropods: among dinosaurs, only theropods were carnivorous; all other dinosaurs were harmless, friendly, bovine-like herbivores (unless of course you were stepped on by one or swatted with their mace-wielding tails).