"The new species is one of the largest fossil penguins described so far and one of the very few giant penguins," said researcher Gerald Mayr.
The parrot may have grown to just over 1 meter (3.3 feet) in height and weighed around 15 pounds, according to researchers.
The origin of avian flight has long-puzzled scientists.
The Neanderthal tooth was found alongside a cave bear bone that may have been carved for a symbolic purpose.
The fossils are 15 million years older than any others belonging to the tyrannosauroid family that have been found in North America.
"You can clearly see the texture of the skin and scales, as well as four-toed claw marks, which are extremely rare," one scientist said.
The clutch of babies were likely still inside their eggs.
Does the foot-long fragment come from a mammoth or a mastodon?
"I was immediately excited, it was just perfect, and I knew it was an important find that needed to be shared with people."
It's been 25 years since the release of "Jurassic Park," and our understanding of dinosaurs has evolved considerably. Paleontologists describe new discoveries and technology enabling a better understanding of dinosaurs since "Jurassic Park" came out in 1993.
The findings could help to shine a light on the evolutionary history of mammals.
The extinct big cat resembled some species you might see in a zoo today, sharing some features with lithe African cheetahs and others with larger, more muscular cats like jaguars and leopards.
Scientists now believe humans stalked and then confronted a giant ground sloth thousands of years ago in New Mexico.
Early dinosaurs were at the mercy of weather patterns unfolding across the supercontinent Pangaea.
"This is a one in 100 million specimen," a University of Kansas fossil expert said.