286 Evolution? The Fossils Say YES!
bones that reinforce the shoulder, which improved flight. They also are the first birds with
a toothless beak. Following this transitional form is another branch point that leads to the
extinct Enantiornithes, or “backwards birds” (so named because their leg bones ossify in
the reverse direction from that found in modern birds). These include Iberomesornis from the
Cretaceous Las Hoyas locality in Spain, Sinornis from China (fig. 12.14C), Gobipteryx from
Mongolia, Enantiornis from Argentina, and several others. All of these birds are more special-
ized than Archaeopteryx, Rahonavis, or Confuciusornis in that they have reduced the number
of trunk vertebrae, have a flexible wishbone, made the shoulder joint better for flying, fused
the hand bones into a bone called the carpometacarpus, and the finger bones into a single
element (the meatless bony part of the chicken wing that you never eat).
Continuing up the cladogram, we come to several Cretaceous birds such as Vorona from
Madagascar, Patagopteryx from Argentina, and the well-known aquatic birds Hesperornis and
Ichthyornis from the chalk beds of Kansas. These birds are united by at least 15 well-defined
characters, including the loss of the belly ribs or gastralia, reorientation of the pubic bone to
the modern birdlike position parallel to the ischium, reduction in the number of trunk verte-
brae, and many other features of the hand and shoulder that improved flight performance.
Ichthyornis is even closer to modern birds in having a keel on its breastbone for the flight mus-
cles and a knob-like head on the upper arm bone that made the wing more flexible. Finally,
the clade that includes all modern members of class Aves is defined by the complete loss of
teeth and a number of other anatomical specializations, such as the fusion of the leg bones to
form a tarsometatarsus.
How do creationists respond to this flood of new discoveries? Most of the time, they
don’t. Even recent books like Sarfati (1999, 2002) and the constantly updated creationist web-
sites completely ignore them. Wells (2000) ignores nearly all of them except for one specimen,
named “Archaeoraptor,” which was a composite forged out of two real fossils by an unknown
Chinese fossil dealer. Smuggled out of China, the specimen was bought and made into a big
deal by amateur dinosaur illustrators (and by National Geographic, which wanted to get a
scoop without waiting for the specimen to be tested by peer review). As soon as well-trained
paleontologists looked at the specimen, they quickly detected that it was a composite of two
different specimens put together to enhance its sale price, and the specimen was never even
formally published in a peer-reviewed journal. Wells (2000) slanders the entire profession by
suggesting that one artful hoax (which was quickly exposed as soon as real paleontologists
looked at it) implies that all the fossils from China are faked or that qualified paleontologists
are easily suckered by fakes. As the facts of the story show, Wells is wrong on all counts.
FIGURE 12.14. In addition to Archaeopteryx, there are now dozens of new transitional birds from the Mesozoic,
each of which shows a mosaic of evolutionary changes from more dinosaur-like creatures like Archaeopteryx to
forms that are similar to modern birds in many ways. (A) Rahonavis from the Cretaceous of Madagascar, which
still has the teeth, long clawed fingers, and long bony tail of Archaeopteryx, but the hip vertebrae are fused to
the hip bones (synsacrum) as in modern birds. (After Forster et al. 1998; copyright © 1998 Association for the
Advancement of Science) (B) Confuciusornis from the Cretaceous of China, which has fused the tail vertebrae
into a pygostyle, and lost its teeth but still has the long dinosaurian fingers. (After Hou et al. 1995; used by
permission of the Nature Publishing Group) (C) Sinornis, a primitive enantiornithine bird from the Cretaceous
of China, which still has teeth, an unfused tarsometatarsus, and an unfused pelvis but had shorter fingers,
a fully opposable big toe for perching, a broad breastbone for flight muscle attachment, and an even shorter
pygostyle in the tail. (From Sereno and Rao 1992: fig. 2. Used by permission of the Nature Publishing Group)