Australopithecus
© From left: Matt Crow/Cleveland Museum of Natural History, John Gurche (facial reconstruction); Dale Omori/Cleveland Museum of Natural History
Among the top fossil discoveries reported this year was this 3.8-million-year-old skull of Australopithecus anamensis (artist’s reconstruction of the hominid, left).

Comment: It's notable that even the language used by the author of Science News reflects how at odds these discoveries are with the conventional theory of evolution. Website Uncommon Descent posted their own commentary in response and which can be found under the relevant points of the article in the yellow boxes.


This year's fossil finds, from vast new collections of species to wonderful and weird curiosities, helped reveal the richness and diversity of life on Earth over the last half a billion years.

1. Impressive invertebrates

518 million years ago

China's Qingjiang biota is a treasure trove of beautifully preserved fossils, including jellyfish (left), comb jellies (middle), mud dragons (right) and arthropods. The remains document the Cambrian explosion, a rapid flourishing of life-forms, and include many organisms never seen before — even at the most famous Cambrian fossil site, Canada's Burgess Shale (SN: 4/27/19, p. 14).
So even more fossils just popped into existence, just like that. No wonder even Darwin had doubts.
Tetrapod

D. Fu et al/Science 2019
2. Tetrapod walking

290 million to 280 million years ago

Using re-created skeletons, fossil trackways, computer simulations and a robot (shown), scientists concluded that four-footed Orobates pabsti held its belly off the ground as it walked with minimal side-to-side undulation. For such an ancient critter, O. pabsti — one of the earliest amniotes, a group that includes reptiles and mammals — had a surprisingly efficient gait (SN: 2/16/19, p. 7).

Turtle

Tomislav Horvat and K. Melo/EPFL Lausanne
So the long, long Darwinian period when the creature just stumbled uncertainly around may have been short or may not have existed? Then what was the mechanism of gait development?

See It takes a smart robot to mimic a reptile.
3. Oldest bone cancer

240 million years ago

A growth preserved in the fossilized left femur of an ancient turtle relative is the oldest known case of bone cancer in an amniote (bracket indicates the tumor on the several-centimeters-long fossil) (SN: 3/16/19, p. 5).

fossil

Y. Haridy et al/JAMA Oncology 2019

4. A bone for chewing


165 million years ago

Millions of years before true mammals emerged, a shrew-sized mammal relative, Microdocodon gracilis (illustrated), had a flexible bone called the hyoid connected to the jaw. The hyoid helps mammals chew, swallow and suckle — a key innovation that may be one secret to mammals' success (SN: 8/17/19, p. 8).

shrew

April I. Neander/Univ. of Chicago


5. Unlaid egg


110 million years ago

A small bird died with an egg (arrow) still inside her body, and problems laying that egg may have led to her death. Crushed and flattened over time by pressure, the specimen is the first unlaid bird egg found preserved as a fossil (SN: 4/13/19, p. 15).

bird fossil

A.M. Bailleul et al/Nature Communications 2019
6. Long-toed bird

99 million years ago

A chunk of amber containing the right leg and foot of a sparrow-sized bird (illustrated) revealed a bizarrely long digit. The bird may have used the toe to feel around for food in hard-to-reach places (SN Online: 7/11/19).
bird

Zhongda Zhang/Current Biology
Possibly the long toe was used for prying things out of holes, like a nut pick. But a more complete fossil record reveals many complexities that challenge simplistic claims and easy explanations of how evolution happens. As research continues apace, any given such theory might be challenged by something just around the corner.
7. Tiny Tyrannosaurus rex cousin

92 million years ago

Decades after its discovery, a dinosaur was ID'd as a cousin to the giant tyrannosaurs. Just a meter tall at the hip, Suskityrannus hazelae (illustrated) had a strong jaw and powerful hind feet, like its bulkier kin T. rex, which lived 24 million years later (SN: 6/8/19, p. 5).

fossil

Andrey Atuchin
8. Life after the dinosaurs

66 million to 65 million years ago

The story of how life rebounded after the mass extinction of nonavian dinosaurs is told by fossils found in Colorado (mammal skulls shown). The fossils, dating to within a million years after the die-off, reveal that mammals grew fivefold in size and big plants rapidly diversified (SN: 12/7/19, p. 32).

lucy fossil

HHMI Tangled Bank Studios
9. Face-off

3.8 million years ago

A nearly complete skull gives the first glimpse at the face of Australopithecus anamensis, the oldest known species in the hominid genus that includes A. afarensis, best known for Lucy's skeleton. The find raises questions about how the two species were related (SN: 9/28/19, p. 6).

australopithecus

Dale Omori/Cleveland Museum of Natural History
10. Little red mouse

3 million years ago

An ancient mouse bears the first identifiable chemical traces of difficult-to-detect pheomelanin, the pigment responsible for reddish-brown fur (SN: 6/22/19, p. 14). X-ray spectroscopy revealed red to brown fur (yellow areas) on the mouse's back and sides.
mouse

P.L. Manning et al/Nature Communications 2019