Ryan Kerney announces the discovery of algae (Oophila amblystomatis) living inside spotted salamander (Ambystoma maculatum) embryo cells — the first discovery of a photosynthetic symbiont living inside vertebrate cells.

Candy makers Hershey and Mars finance competing genomic sequences for cacao (the primary ingredient of chocolate).

Robert G. Edwards receives the Nobel prize in Medicine "for the development of in vitro fertilization"

Abderrazak El Albani and colleagues describe 2.1-billion-year-old macroscopic fossils from Gabon. The authors argue that the fossils are multicellular, pushing back the record of macroscopic life by more than 200 million years. The team also contends that the complex shapes of the fossils suggest cell signaling and coordinated growth.

Adam Brumm, Mike Morwood and colleagues publish a paper arguing that more than 40 stone artifacts found in situ and dated to approximately 1 million years ago indicate that the ancestors of Homo floresiensis (the "hobbits") arrived on Flores some 120,000 years earlier than previously thought.

Bulldozer operator Jesse Steele uncovers bones while digging a reservoir in Snowmass, Colorado. Excavations at the site will turn up more than 40 kinds of Ice Age animals.

Grzegorz Niedzwiedzki and colleagues publish a description of 395-million- year-old tetrapod tracks from Poland — 18 million years before tetrapods were thought to exist. The tracks' early date, large size and marine environment cause some skepticism about the find.

In the same week, separate research teams announce the finds of a 100- million-year-old mammal hair preserved in amber, and a 30-million-year- old pelican fossil with a 30-centimeter-long beak.

Meijer and Due announce the discovery of a 1.8-meter-tall, 16-kilogram, likely landlubbing, carnivorous stork (Leptoptilos robustus) on the island of Flores. Whether the storks ate Homo floresiensis juveniles, the hobbits hunted the storks, or everybody left each other alone is unresolved.

Nicholas Longrich describes a new dinosaur species from previously misidentified fossils at the American Museum of Natural History. Perhaps nudged by drinking buddies, he names the ceratopsian — with pretty heart shapes in its crest — Mojoceratops.

Scott Sampson and colleagues describe two species of exuberantly horned ceratopsian dinosaurs from late Cretaceous sediments in Utah: Utahceratops gettyi and Kosmoceratops richardsoni.

The Smithsonian opens its new human origins hall. A week later, Johannes Krause and colleagues announce the find of a fossil finger fragment from an unknown hominid from Siberia coincident with Neanderthals and modern humans (later dubbed Denisovans, and found distantly related to modern New Guineans). A few weeks after that, Lee Berger and colleagues announce the find of a new hominid from South Africa, Australopithecus sediba. Several weeks later, an international team announces a small DNA overlap between modern humans and Neanderthals that suggests interbreeding.

Two studies released in the same week indicate that modern Melanesians and Aboriginal Australians descended from an earlier migration out of Africa than did other populations. Further, the studies suggest that participants in the earlier migration interbred with Denisovans.

Bruce A. Beutler and Jules A. Hoffmann share the Nobel Prize in Medicine "for their discoveries concerning the activation of innate immunity"

Bruce Archibald and coauthors describe a hummingbird-sized flying ant species that hopped continents during the early Eocene.

Darren Naish and coauthors describe a 27.5-centimeter bird jaw from the Late Cretaceous found in Kazakhstan. With only the jaw, the paleontologists can't be sure whether it loped like an ostrich, or pelted unfortunate land lubbers with effluvia missiles from above.

Jianni Liu and colleagues describe Diania cactiformis, or "walking cactus." It's a kind of leggy worm known as a lobopodian that lived in the Cambrian Period some 520 million years ago. The authors indicate that it might be close to the ancestral line for arthropods — jointed animals ranging from lobsters to ladybugs.

John Paterson and coauthors report their findings on Anomalocaris, a meter- long Cambrian predator so weird its remains were once mistaken for a shrimp and a jellyfish. They find that its eyes, mounted on the ends of stalks, were compound eyes, each with 16,000 separate lenses. Like dragonfly eyes but supersized.

Junchang Lü and colleagues announce the find of a Jurassic fossil from China, a probable female pterosaur who died while laying an egg. The egg is tiny compared to the mother, and has a parchment-like eggshell. The find suggests that pterosaurs buried their eggs, and that females lacked head crests.

Lee Berger and coauthors publish several papers on Australopithecus sediba arguing that the species is a direct ancestor of modern humans and the family tree will need to be redrawn. Other paleoanthropologists aren't so sure. They do agree that the Sediba's weird mix of primitive and advanced features demonstrates remarkable hominid diversity.

Longrich and Olson describe a newly discovered wing feature on an extinct, flightless Jamaican bird named Xenicibis: built-in nunchucks.

Michael Waters and coauthors describe a stone tool assemblage at the Buttermilk Creek Complex in Texas documenting the presence of humans in the New World about 15,500 years ago — more than 2,000 years before the earliest Clovis sites.

On the sesquicentennial of its discovery, a new study challenges the status of Archaeopteryx as the earliest known bird. Xing Xu and coauthors argue that Archaeopteryx and newly discovered Xiaotingia are closer to nonavian dinosaurs. Reactions to the paper are mixed.

Relying on molecular dating and some (literally) lousy fossils, Vincent Smith and colleagues assert that lice have been rapidly evolving since well before the end of the Cretaceous, and may have hung out on feathered dinosaurs before annoying other species.

Esther Ullrich-Lüter and colleagues describe photoreceptors in sea urchin tube feet, meaning the animals may have functioned as big, compound eyes.

Sir John B. Gurdon and Shinya Yamanaka share the Novbel Prize in Medicine "for the discovery that mature cells can be reprogrammed to become pluripotent"

A boy named Evgeniy Solinder discovers a well-preserved mammoth in the Siberian Arctic. Later examination will show evidence that the mammoth was killed by spear-wielding humans, and radiocarbon dating will indicate that the animal is 45,000 years old, pushing back the earliest known human occupation of the region by 10,000 years.

After examining fossil feathers with an electron microscope and comparing them to modern feathers, a team of American and Chinese scientists announces that Microraptor, a four-winged dinosaur from China probably had an iridescent sheen to its feathers.

Chinese and Canadian researchers announce the discovery of Yutyrannus huali, a distant T. rex relative in which the 1.5-ton adult still sported long filamentous feathers.

Clive Finlayson and coauthors argue that Neanderthals collected bird feathers for use in personal adornment.

Extrapolating from contemporary cows, a team of British scientists contends that sauropod flatulence, releasing the potent greenhouse gas methane, played a significant role in the Mesozoic's warm, moist climate.

Gregory Retallack publishes a paper arguing that Ediacaran fossils long thought to be marine animals were actually land-based lichens. His argument pushes back the beginning of land-based life by 65 million years. Anticipating "sharp intakes of breath in the paleontological community," Nature sets up a comment forum at the same time it publishes Retallack's paper.

Two studies, released the same week in Science and Nature and done partly by the same researchers, describe two groups of ancient tools from South Africa. The studies say that one group, estimated to be about 71,000 years old, has small bladelets likely made from heat-treated stone, and the other group, estimated to be about 500,000 years old, has spear tips.

Walter Joyce and coauthors announce a new discovery in Germany's Messel Pit, a famous Eocene fossil site. The discovery includes multiple pairs of fossil turtles petrified in a state of indelicacy.

A team of British and U.S. scientists describe the color mechanism of a brilliant iridescent blue African fruit, Pollia condensata. Like some beetle shells, butterfly wings, and bird feathers, the fruit gets its color from microscopic structures rather than pigments, but the fruit's coiled strands of cellulose are like nothing before discovered in nature.

An international team of researchers publishes a study indicating that aphids might be able to engage in a photosynthesis-like process, using carotenoids for the "capture of light energy."

Eric Rittmeyer and coauthors describe Paedophryne amauensis, a 7.7- millimeter-long frog from New Guinea, "the smallest known vertebrate species."

Frank Glaw and coauthors describe several new species of miniature chameleons from Madagascar. Among the tiniest is Brookensia micra, with juveniles little enough to stand on the head of a match.

While sorting and relocating the Cambridge Herbarium, a university librarian finds fungi and seaweed collected by Charles Darwin on his Beagle voyage, still wrapped in newspaper from 1828.

Based on new genetic research, David Reich, Svante Pääbo and collaborators announce at a Royal Society of London meeting that Denisovans bred with Neanderthals, ancestors of people now living in East Asia and Oceania, and another group of extinct archaic humans who were genetically dissimilar to both Neanderthals and modern humans. A few weeks later, Matthias Meyer, Svante Pääbo and coauthors describe the oldest hominin DNA sequence to date, from a 400,000-year-old femur from Spain's Sima de los Huesos. The mitochondrial DNA indicate an unexpected link to Denisovans.

Using genetic material from more than 300 individuals, including aboriginal Australians from the Northern Territory, a team of geneticists argues that Australians — long believed isolated from other populations for some 45,000 years — received substantial gene flow from India about 4,230 years ago.

James E. Rothman, Randy W. Schekman and Thomas C. Südhof share the Nobel Prize in Medicine "for their discoveries of machinery regulating vesicle traffic, a major transport system in our cells"

Dale Greenwalt and coauthors describe a 46-million-year-old fossil female mosquito from Montana with traces of her last bloody meal (iron and porphyrin) in her bloated abdomen — strong evidence that these bugs have been irritating nicer animals for tens of millions of years.

David Legg describes a Cambrian arthropod with scissor-like front appendages. He names the species Kootenichela deppi after Johnny Depp.

David Lordkipanidze and coauthors publish a new paper on the hominid fossils from Dmanisi, Georgia. They argue that all the fossils from the site are Homo erectus, and make the controversial claim that hominid species found worldwide from that period — Homo erectus, Homo habilis, and Homo rudolfensis — might all belong to one species with a lot of variability.

Marie Soressi and coauthors contend that Neanderthals made leather-working tools similar to modern-day lissoirs used on pricey handbags.

Reporting on some 12 years of research at La Chapelle-aux-Saints, William Rendu and coauthors support the original interpretation of intentional Neanderthal burials. They conclude that the burial pits are not explained by natural processes and, unlike the site's scavenged animal bones, the relatively undamaged human remains at the site must have been buried quickly.

Robert DePalma and coauthors describe a likely T. rex tooth lodged between hadrosaur vertebrae. The authors also describe regenerated bone that "massively overgrew" after the hadrosaur was bitten. They cite the find as evidence that T. rex hunted, at least some of the time, and that this lucky hadrosaur lived to munch leaves another day.

Robert Reisz and collaborators announce the "discovery of an embryonic dinosaur bone bed from the Lower Jurassic of China, the oldest such occurrence in the fossil record." The find includes the remains of many individual dinosaurs at different stages of development.

John O Keefe, May-Britt Moser and Edvard I. Moser share the Nobel Prize in Medicine "for their discoveries of cells that constitute a positioning system in the brain"

After reexamining mussel shells collected by Eugène Dubois in Indonesia in the 1890s, a team of researchers announces that one of the shells bears the oldest-yet-known geometric engraving. They date the shell at around 500,000 years and attribute the handiwork to Homo erectus.

Ainara Sistiaga and colleagues describe what they contend is the oldest human coprolite yet positively identified: a roughly 50,000-year-old Neanderthal calling card from El Salt, Spain. Their analysis indicates that Neanderthals balanced their meaty diets with nuts, berries and vegetables. Other researchers find the study intriguing but hope for confirmation that the fossil turd is from a human and not, say, a bear.

An international research team announces the age of Indonesian cave art, originally discovered in the 1950s. The authors state that radiometric dating indicates the artwork is about 40,000 years old, making it comparable in age to the oldest reliably dated art found in Europe. The authors describe one hand stencil from Sulawesi's Maros karsts as "the oldest known hand stencil in the world."

Matt Lamanna and coauthors describe Anzu wyliei, an bipedal, bird- like feathered dinosaur found in North and South Dakota. Measuring 11 feet and 500 pounds, the oviraptorosaur is nicknamed the "chicken from hell."

Nick Ashton and coauthors describe human footprints discovered along England's east coast in May 2013 — exposed and eroded by ocean water in a matter of weeks. Based on the geologic setting, the researchers estimate the tracks at about 800,000 years old (making them the oldest hominid footprints yet found outside Africa), and suggest the footprints might have been left by Homo antecessor.

Nizar Ibrahim, Paul Sereno and collaborators describe the aquatic adaptations of Spinosaurus, a massive carnivorous dinosaur species first studied by Ernst Stromer around 1912. Citing the animal's tiny nostril high on the head, dense limb bones, long forelimbs and flat feet, the authors argue that the dinosaur lived a semiaquatic life.

Researchers affiliated with the Museum of Paleontlogy Egidio Feruglio announce the discovery of the biggest dinosaur yet discovered: a seven- storey-tall titanosaur from Patagonia. A few months later, an international research team names the species Dreadnoughtus schrani, and states that multiple aspects of the skeleton indicate the animal was still growing when it died.

Xiaoya Ma and coauthors describe a well preserved 520-million-year-old fossil arthropod of the species Fuxianhuia protensa. The team identifies the animal's circulatory system from dark carbon lines in the fossil. The researchers argue that this fossil preserves the oldest cardiovascular system yet known, and that complex cardiovascular systems evolved early in the Cambrian Period.

Bryan Sykes and colleagues publish their DNA analysis of 37 hair samples purported to be remains of Bigfoot or Yeti, collected from Russia, the Himalaya and the United States. They announce that two samples match the DNA of fossil polar bears, and the rest match animals such as dogs, cows, horses, raccoons, and goat-like serows.

Bhart-Anjan Bhullar, Arhat Abzhanov and colleagues announce that they have reverse engineered dinosaur snouts in chicken embryos by altering beak- building gene expressions.

Stephen Hackley publishes a review article arguing that human brains retain vestigial neural circuitry, the same circuitry that currently allows other mammals (and once allowed our ancient ancestors) to orient their ears toward novel stimuli.

William C. Campbell and Satoshi Omura share the Nobel prize in Medicine "for their discoveries concerning a novel therapy against infections caused by roundworm parasites" and Tu Youyou receives a Nobel {rize in Medicine "for her discoveries concerning a novel therapy against Malaria"

A team led by Sonia Harmand announces the discovery of stone tools at Lomekwi, Kenya, estimated to be 3.3 million years old, meaning older than the genus Homo. The heaviest of the tools prompt archaeologist David Braun to ask about their makers, "What the hell do these things look like if they can use 15-kilogram tools?"

After recruiting skinny spelunkers to excavate a cave he can't reach, and recruiting "early career scientists" to interpret the fossils, Lee Berger, with his coauthors, announces Homo naledi from South Africa. Berger and coauthors suggest that the hominid might be more than 2 million years old and that it might have intentionally disposed of its dead. In an accompanying commentary, Chris Stringer expresses surprise at "the apparent lack of attempts" to date the fossils.

After studying Chinle Formation rocks at Ghost Ranch, New Mexico, Jessica Whiteside and coauthors argue that weather extremes, drought and fires kept dinosaurs from dominating Earth's tropics for the first 30 million years of the Mesozoic Era.

An international research team announces that Sterkfontein Cave's "Little Foot," classified as Australopithecus prometheus, is 3.67 million years old, making the fossil older than the iconic Lucy.

An international research team describes Aegirocassis benmoulae, a 480- million-year-old arthropod similar to Anomalocaris that might have measured as much as 2 meters (6 feet) long. Found in Morocco, the fossils have been preserved in three dimensions, and indicate that the giant arthropod was a filter feeder.

Based on new specimens from Burgess Shale, Martin Smith and Jean-Bernard Caron describe the elusive head of the Cambrian animal Hallucigenia, noting that it is shaped like a spoon with "a really cheeky semicircular smile" next to multiple appendages. They also note that what had previously been mistaken for the head was at the other end of the body — "decay fluids" squeezed out of the gut during fossilization.

Caleb Brown and Donald Henderson describe Regaliceratops peterhewsi, a new species of ceratopsid dinosaur that they have nicknamed "Hellboy."

Emily Mitchell and coauthors hypothesize that Fractofusus, an Ediacaran Period rangeomorph (unlike a modern plant or animal, but big enough to leave a distinctive fossil), reproduced in two ways: by sprouting clones from its body, and by releasing propagules (akin to seeds) into the ocean water.

Fernando Novas and coauthors describe Chilesaurus diegosuarezi, a "bizarre herbivorous" theropod, i.e., a member of a group of typically carnivorous dinosaurs, from Jurassic-aged rocks in Chile. The dinosaur species is named for Diego Suárez, who found the first fossil bones in the rock formation when he was seven years old.

James Lamsdell and coauthors describe the oldest-yet-known sea scorpion (eurypterid), from 467-million-year-old rocks in Iowa. The researchers state that Pentecopterus decorahensis grew to over 5 feet long and, unlike any other arthropod known (living or extinct), radically changed limb shape during the growth process. The authors suggest that eurypterids either diversified very quickly, or originated much earlier than previously thought.

Nohemi Sala and coauthors describe a 430,000-year-old skull from Spain's Sima de los Huesos Cave bearing two fractures indicative of deadly blunt- force trauma. The authors describe the find as "the earliest evidence of lethal interpersonal violence in the hominin fossil record."

Silvia Danise and Nicholas Higgs describe trace fossils suggesting that the marine worm genus Osedax fed on the bones of Cretaceous plesiosaurs that fell to the ocean floor 100 million years ago. They hypothesize that the genus of the species Osedax mucofloris ("bone-eating snot flower" first described in 2005) ate the bones of Mesozoic marine reptiles and sea turtles before whales evolved into the worms' favorite food.

Xiaoya Ma and coauthors argue that brain tissue has been fossilized in seven specimens of the Cambrian arthropod Fuxianhuia protensa from the Chenjiang fossil beds in southwest China.

Xing Xu and colleagues describe Yi qi, a small Jurassic dinosaur with weird rod-like bones projecting from its wrists, and traces of membranes. The researchers assert that the rod-like bones might have supported membranes that might have been used in flight, but probably just gliding. They also note that the dinosaur had a relatively heavy behind and would have occasionally stalled.

A team of scientists describes Acmella nana collected from the forests of Borneo. The shells range in size from 0.60 to 0.79 millimeters, roughly 0.30 millimeters smaller than the previous tiniest-snail-species record holder identified just a month before.

Jérémie Teyssier and coauthors attribute panther chameleons' ability to quickly change color to their ability to rapidly tune a network of photonic crystals under their skin. The authors also argue that a deeper layer of larger crystals in the chameleons' skin reflects sunlight, especially in the near-infrared. In short, the crystals keep the chameleons both cool and colorful.

Nature publishes "Here Be Dragons" explaining that medieval dragons, who engaged in a centuries-long slumber encouraged by the Little Ice Age and "a bewildering lack of knights," might undergo a resurgence due to global warming since higher temperatures benefit "buccal and nasal furnaces." The article is published online on April 1 with the editorial note that "some of its content may merit a degree of scepticism."

Yoshinori Ohsumi receives the Nobel prize in Medicine "for his discoveries of mechanisms for autophagy"

A team led by Victoria McCoy publishes an analysis of Tullimonstrum gregarium (the Tully monster, originally found in 1955) concluding that the animal was a vertebrate related to lampreys. One of the paper authors, Carmen Soriano, remarks, "If you put in a box a worm, a mollusk, an arthropod and a fish, and you shake, then what you have at the end is a Tully monster."

Allen Nutman and colleagues argue that a group of metamorphic rocks from the Isua Supracrustal Belt in southwest Greenland preserve 3.7-billion- year-old stromatolites. If the claim is correct, the fossils are the oldest so far discovered, but other researchers express doubts.

Błażej Błażejowski and coauthors argue that Trimerocephalus chopini, 365-million-year-old eyeless Devonian trilobites, migrated by forming single-file lines, keeping their queues together through touch and/or chemical signals such as pungent urine.

David Norman and colleagues announce that a mineral lump found on a Sussex beach in 2004 is fossilized brain tissue from a 133-million-year-old dinosaur, perhaps an Iguanodon or related species.

Elizabeth Martin-Silverstone and coauthors describe fossil pterosaur fragments (an upper arm bone and some vertebrae) from Hornby Island, British Columbia. The researchers state that the internal structure of the humerus and the partially fused condition of the vertebrae suggest the individual was nearly full grown when it died, and had a wingspan of just 1.5 meters (5 feet). If the pterosaur was as little as the researchers suspect, then when it was perched, it would be about as short as a house cat.

Frido Welker and coauthors argue that 40,000-year-old jewelry, collected decades earlier from Arcy-sur-Cure, was made by Neanderthals. The researchers base their claim on the amino acids found in the collagen of bone fragments associated with the ancient bits of bling — amino acids indicative of Neanderthals as opposed to archaic humans.

Gerrit van den Bergh and coauthors announce the find of Homo floresiensis- like fossils from a new site on the island of Flores, about 50 miles east of the 2004 "hobbit" discovery site. The new find, including a partial mandible and some teeth, is estimated at 700,000 years old, more than half a million years older than the fossils found in 2004.

John Kappelman and colleagues claim that the Australopithecus africanus specimen Lucy fell from a tree more than 30 feet high, dying in the fall that left observable fractures in her fossil bones. The claim attracts skepticism from Donald Johanson and Tim White, members of the original Lucy discovery team.

Lida Xing and coauthors describe the feathered tail of a theropod dinosaur, perhaps a young coelurosaur. The fossil is preserved in Cretaceous amber from Myanmar (Burma).

Mary Higby Schweitzer and coauthors publish a study of medullary bone (known as a ready-to-use source of calcium for making eggshells in modern birds) in a Tyrannosaurus rex fossil. The researchers argue that the medullary tissue shows that this T. rex was not only female but also pregnant.

Mikkel Pedersen and coauthors argue that Beringia did not shed glaciers and gain vegetation early enough to support the ancestors of Clovis people, though later migrants to the Americas might have traveled that route.

Nichole Gunter and coauthors hypothesize that dung beetles probably evolved during the Cretaceous Period to eat dinosaur poo, and that "the switch in dinosaur diet to incorporate more nutritious and less fibrous angiosperm foliage provided a palatable dung source that ultimately created a new niche for diversification."

Julius Nielsen and coauthors publish an account of the longest-lived vertebrate so far discovered: a Greenland shark (Somniosus microcephalus) that ranges in age from 272 to 512 years old.

Jeffrey C. Hall, Michael Rosbash and Michael W. Young share the Nobel Prize in Medicine "for their discoveries of molecular mechanisms controlling the circadian rhythm"

A Chinese-U.S. team announces the discovery of two hominid skullcaps, 105,000 to 125,000 years old, from eastern China. Although the researchers don't assign the crania to any species, some of their peers speculate that the fossils might be Denisovan.

After studying von Ebner lines (microscopic daily growth lines in teeth) from Protoceratops andrewsi and Hypacrosaurus stebingeri embryos, Gregory Erickson and coauthors argue that the dinosaurs had months-long gestation periods, developing more like slow-growing reptiles than fast-growing birds.

An international research team describes a well-preserved baby bird specimen in a 99-million-year-old piece of amber collected from Burma. The scientists classify the hatchling as a member of the enantiornithes, extinct relatives of modern birds that still had clawed wings and teeth.

An international team describes California's Cerutti Mastodon site, found in 1992. The researchers argue that the assemblage of broken mastodon bones and rocks comprises evidence of human activity. Based on measures of radioactive uranium and thorium in the bones, they argue that the site is 130,000 years old. Because this date is generally understood to precede modern Homo sapiens spreading beyond Africa, the paper suggests that Neanderthals, Denisovans or even late Homo erectus might have reached North America via the Bering Land Bridge and Pacific Coast. Nature, the paper's publisher, calls the study a "jaw-dropping claim." Parties to the announcement anticipate skepticism.

Darren Naish and Mark Witton describe a robust cervical verterbra from the Transylvanian azhdarchid pterosaur Hatzegopteryx. The researchers argue that the animal had a short, thick neck that could withstand torsion and compression, and could bear heavy loads. Considering the fossil locality (the Romanian town of Haţeg) was an island during the Cretaceous, and therefore lacked typical terrestrial predators, the authors contend that Hatzegopteryx might have occupied the top of the food chain. Witton describes these pterosaurs as "giraffe-sized, quadrupedal Panzer- storks."

Gerald Mayr and colleagues describe a 150-centimeter- (60-inch-) long, 61- million-year-old fossil penguin, almost the biggest fossil penguin ever found, and the oldest of that size. The researchers state that this fossil's differences from more primitive penguins implies that penguins arose earlier than previously thought, probably during the Mesozoic.

Thomas Hegna and coauthors describe possible eggs from a roughly 450- million-year-old pyritized trilobite, Triarthrus eatoni. The tiny eggs are clustered near the animal's head, indicating that the head was the gamete-ejection point.

James P. Allison and Tasuku Honjo share the Nobel Prize in Medicine "for their discovery of cancer therapy by inhibition of negative immune regulation"

(no entry for this year)