The Evolution of Birds, from Archaeopteryx to the Passenger Pigeon

Titanis (Dmitri Bogdanov)

To many avid readers, Titanis will be familiar as the predatory bird in James Robert Smith's best-selling novel (and soon-to-be-movie) The Flock. This prehistoric bird could certainly wreak its share of mayhem: at eight feet tall and 300 pounds (give or take a few inches and pounds for possible sexually dimorphic differences between males and females), Titanis closely resembled its theropod dinosaur forebears, especially its puny arms with long-taloned, grasping hands.

As scary as it was, though, Titanis wasn't the most dangerous hunting bird of ancient times: in fact, it was a late, North American descendant of a race of South American carnivores, the phorusrachids (typified by Phorusrhacos, also known as the Terror Bird), which attained comparable sizes. By the early Pleistocene epoch, about two million years ago, Titanis had managed to penetrate as far north as Texas and southern Florida, the latter of which is The Flock's modern-day setting.

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Bob Strauss is a freelance writer and book author; one of his specialties is explaining scientific concepts and discoveries to both a lay and professional audience.

Bob Strauss is the author of two best-selling question-and-answer books that range across the expanse of science, biology, history and culture: The Big Book of What, How and Why (Main Street, 2005) and Who Knew? Hundreds & Hundreds of Questions & Answers for Curious Minds (Sterling Innovation, 2007).

The Evolution of Birds, from Archaeopteryx to the Passenger Pigeon

 

The Thunder Bird, Dromornis (Nobu Tamura)

Perhaps for tourism purposes, Australia has been doing its best to promote the Thunder Bird as the largest prehistoric bird that ever lived, proposing an upper-bound weight for adults of a full half a ton (which would vault Dromornis over Aepyornis in the power ratings) and suggesting that it was even taller than the Giant Moa of New Zealand. Those may be overstatements, but the fact remains that Dromornis was a huge bird, surprisingly not related as much to modern Australian ostriches as to smaller ducks and geese.

Unlike these other giant birds of prehistoric times, which (because of their lack of natural defenses) succumbed to hunting by early human settlers, the Thunder Bird seems to have gone extinct all on its own--perhaps because of climatic changes during the Pliocene epoch that impacted its presumed herbivorous diet.

_______________________________________________________________________________
Check out Bob's Dinosaur Blog !

Bob Strauss is a freelance writer and book author; one of his specialties is explaining scientific concepts and discoveries to both a lay and professional audience.

Bob Strauss is the author of two best-selling question-and-answer books that range across the expanse of science, biology, history and culture: The Big Book of What, How and Why (Main Street, 2005) and Who Knew? Hundreds & Hundreds of Questions & Answers for Curious Minds (Sterling Innovation, 2007).

The Evolution of Birds, from Archaeopteryx to the Passenger Pigeon

Kelenken (Wikimedia Commons)

A close relative of Phorusrhacos--the poster genus for the family of extinct feathered carnivores known as "terror birds"--Kelenken is known only from the remains of a single, oversized skull and a handful of foot bones described in 2007. That's enough for paleontologists to have reconstructed this prehistoric bird as a mid-sized, flightless carnivore of the mid-Miocene forests of Patagonia, although it's as yet unknown why Kelenken had such a huge head and beak (probably it was another means to intimidate the mammalian megafauna of prehistoric South America).

_______________________________________________________________________________
Check out Bob's Dinosaur Blog !

Bob Strauss is a freelance writer and book author; one of his specialties is explaining scientific concepts and discoveries to both a lay and professional audience.

Bob Strauss is the author of two best-selling question-and-answer books that range across the expanse of science, biology, history and culture: The Big Book of What, How and Why (Main Street, 2005) and Who Knew? Hundreds & Hundreds of Questions & Answers for Curious Minds (Sterling Innovation, 2007).

The Evolution of Birds, from Archaeopteryx to the Passenger Pigeon

Terror Bird: Adalgalornis

Andalgalornis (John Conway)

As "terror birds"--the oversized, flightless apex predators of Miocene and Pliocene South America--go, Andalgalornis isn't quite as well known as Phorusrhacos or Kelenken. However, you can expect to hear more about this once-obscure predator, because a recent study about the hunting habits of terror birds employed Andalgalornis as its poster genus. It seems that Andalgalornis wielded its large, heavy, pointed beak like a hatchet, repeatedly closing in on prey, inflicting deep wounds with quick stabbing motions, then withdrawing to a safe distance as its unfortunate victim bled to death. What Andalgalornis (and other terror birds) specifically did not do was grasp prey in its jaws and shake it back and forth, which would have placed undue strain on its skeletal structure.


____________________________________________________________________
Check out Bob's Dinosaur Blog !

Bob Strauss is a freelance writer and book author; one of his specialties is explaining scientific concepts and discoveries to both a lay and professional audience.

Bob Strauss is the author of two best-selling question-and-answer books that range across the expanse of science, biology, history and culture: The Big Book of What, How and Why (Main Street, 2005) and Who Knew? Hundreds & Hundreds of Questions & Answers for Curious Minds (Sterling Innovation, 2007).