Do dinosaurs and birds flock together?

“Jurassic Park” Velociraptors, in all their calculated menace, don’t scare Alan Feduccia.

Instead, the Carolina evolutionary biologist regards them among the inaccurate reasons why other scientists erroneously claim that birds evolved from dinosaurs.

The question of whether birds are living dinosaurs is one that Feduccia, former chair of Carolina’s biology department in the College of Arts & Sciences and S. K. Heninger Distinguished Professor Emeritus, has researched for decades. Feduccia began seeking answers in the 1970s before publishing “The Age of Birds” in 1980.

The debate was just beginning then as fossils of the crow-sized Archaeopteryx, first discovered in 1861, and its feathery features had paleontologists naming birds as dinosaur descendants. The direct-descendant concept is now entrenched in museums and textbooks.

His fourth and newest book “Romancing the Birds and Dinosaurs” offers more answers while disputing theories that avian flight originated from the ground up and that fossilized raptors with feathers were true dinosaurs. The book’s 23 short essays also support the “Neoflightless Hypothesis” that so-called feathered dinosaurs are instead “hidden birds” such as four-winged microraptors and flightless forms such as ostrich-like species that superficially resemble dinosaurs.

“This is not a trivial question,” Feduccia said, “When you go with dinosaurs being direct ancestors of birds, a cascade of biological improbabilities confronts you. It requires fitting lots of square pegs into round holes.”

Alan Feduccia’s research included studying the embryology of ostrich eggs. (Photo by Jason Smith, UNC Endeavors)

A problematic tree of life

Feduccia thinks that today’s tree-of-life method of fossil classification called phylogenetic systematics is replete with problems.

“It’s a straitjacket methodology that attempts to resolve the evolutionary branching sequence. The consequence is that all biological interpretations must conform to the phylogeny or tree, and if the tree is wrong, then all the inferences from it will be also,” Feduccia said.

The methodology can yield distortions because, according to Feduccia:

• It cannot detect convergent evolution, a common phenomenon when organisms not closely related to each other independently acquire similar characteristics while adapting to similar environments;
• studying deteriorated fossils and incomplete fossilized skeletons ─ only about 15% of an animal’s body mass ─ can yield unreliable findings; and
• arrested development, common in vertebrates, distorts the phylogeny.

“There is a very small percentage of a skeleton on which to base these tremendous conclusions,” Feduccia said. “The whole genome analysis of living birds has shown at least 20 huge mistakes in conflict with phylogenetic systematics. The methodology has been widely hailed as the answer for developing a tree of life and it’s just not working.”

Improbable origins of flight

Dinosaurs are characterized by a large pelvic region, large balancing tail and short forelimbs that are about one half the length of their hind limbs. Feduccia sees no logical answer for how dinosaurs with such short limbs evolved into birds.

“Re-evolving lost structures such as long forelimbs is highly improbable and would invalidate a biological axiom known as Dollo’s Rule on the improbability of re-evolving the same long-vanished structures once the genetic and developmental machinery has disappeared,” Feduccia said.

Another problem: viewing birds as ancestors of ground-dwelling dinosaurs means that avian flight began from the ground up. “That’s not only improbable, but practically impossible,” Feduccia said.

“Imagine running along trying to figure out how to get off the ground. Flight requires thrust and lift, not flapping little, short limbs. Much of this was discredited early on, but a lot of people have come up with all sorts of weird ideas on how flight evolved from the ground up.”

Flight starting in trees or high places is a more plausible origin, first proposed by Charles Darwin for bats, Feduccia said. “It takes advantage of the cheap energy that gravity provides.”

The cascade of improbabilities includes dinosaurs developing sophisticated aerodynamic feathers, an avian flight hand, a flight cerebellum for equilibrium and flight inner ear prior to the need to fly. For a bird’s aerodynamically engineered perfection to evolve in a non-flight context is practically non-Darwinian, Feduccia said. “How do you select for something before it has its current function? There’s a term for that, and it occasionally occurs. It’s called an exaptation, but it’s very unusual.”

Another point of contention is so-called protofeathers, first described in Nature in 1996, which the “dinosaur as origin of birds” concept posits, evolved before flight as micro feathers or little filaments to eventually become feathers. Feduccia says scant evidence exists for this and, instead, provides evidence that protofeathers on ancient dinosaurs were collagen fibers, ossified tendons or other filament-like structures with no connection to true bird feathers.

Paleontologists err, Feduccia said, by claiming that such an extraordinarily complex aerodynamic structure evolved before flight for something other than aerodynamics. “It’s evolutionary overkill,” he said. “If feathers evolved, let’s say, for insulation, which is one of the main reasons they claim, that would be equivalent to insulating an ice truck with the heat shield from the space shuttle.

Instead, Feduccia looks for a simple, logical explanation. “Evolution doesn’t waste all this developmental and anatomical energy to produce a structure that’s not exactly suited to the right function.”

“Avian feathers are the most perfect and complex aerodynamic structure ever invented by the vertebrate skin or integumentary.” That system includes skin, scales, feathers, hair and glands.

“Everything about them screams out aerodynamic refinement,” Feduccia said. Feathers’ features include:

• lightweight and extreme flexibility;
• furrowed lower shaft for more weight-bearing strength;
• ability, when broken, to knit together like Velcro;
• narrow outer vein that produces an airfoil cross-section to aid flight; and
• laminar flow, meaning that air moves smoothly across layers to reduce drag.

Movies, blogsters and bizarre art

Beginning in the 1990s, the combination of dinosaur movies, amateur paleontologist blogsters and artists portraying dinosaurs in bizarre forms and doing things that require intelligence fed opposition to Feduccia’s theories.

“These were not the brightest animals that ever lived,” he said. “They’re programmed to eat and sleep and eat. Movies like ‘Jurassic Park’ portray dinosaurs far beyond their activity patterns and thinking abilities. Tyrannosaurus rex, despite what paleontologists might say, had a pea-brain like an alligator’s.”

And amateur paleontologists? “Blogsters took hold of the field with literature that has no peer review. They write it and it ends up on the Web. Some of them are sponsored by respectable magazines like Discover, the Smithsonian Magazine and Scientific American. The stuff becomes acceptable science. That’s had a destructive effect on this field.”

Recent books about studying birds as living dinosaurs at the backyard bird feeder concern Feduccia. He takes issue with the theory that because hot-blooded or endothermic birds descended from dinosaurs that dinosaurs in turn were also hot-blooded. “Dinosaurs, including Tyrannosaurus rex, have ectothermic or cold-blooded growth rings in the long bones, just like tree rings, as do the early birds like the Archaeopteryx. That’s a reptilian feature, characteristic of cold-blooded animals,” he said. Such refuted “half-truths” add up to a whole truth for some people, Feduccia said.

“Rambo and Clementine: Thanks for the Thumb”

For his embryological research, Feduccia used eggs from an ostrich farmer in eastern North Carolina. A female named Clementine and a male named Rambo did their part, so Feduccia named one of the book’s essays after them.

The essay describes the research that contradicts the birds-as-dinosaurs theory by showing differences in how bird and dinosaurs develop digits. Feduccia’s years-long study of ostrich embryology found that unlike dinosaurs with their grasping, raking hand with a thumb and two adjacent digits — birds develop what humans consider to be a hand’s three middle digits.

“It’s unequivocal and a major disparity between birds and dinosaurs. People have tried to claim that there was some major, almost magical shift of digits in the hand’s evolution without explanation, but it is improbable and a contravention of embryological principles. If birds were already dinosaurs, they would have had the same hand to begin with.”

Hidden birds

Feduccia came up with the phrase “hidden birds” in 2012’s “Riddle of the Feathered Dragons” to describe so-called “feathered dinosaurs” like Archaeopteryx. He also applies the term to flightless forms that resemble ostriches, and the so-called flying dinosaurs, the four-winged microraptors.

“Birds become secondarily flightless, a very common phenomenon, through arrested development or pedomorphism. It just means the developmental time is reduced.” Through pedomorphosis, an organism retains juvenile or even larval traits into later life. Such birds may resemble large chicks.

“When I called them secondarily flightless birds instead of feathered dinosaurs, the dinosaur people freaked out. ‘No, it’s a dinosaur because our methodology shows that it is a dinosaur,’ they said,” Feduccia said.

He borrows from philosopher Arthur Schopenhauer to describe how his ideas have been received. “I’m always encouraged by Schopenhauer saying that new ideas pass through three stages. First, there’s ridicule. I’ve been through that. Second, there’s outrage. I’ve been through that. And third, the idea is accepted as being self-evident.”