Category Archives: paleobiology

Oldest “bilaterian” found: wormlike creature discovered along with its tracks

One of the big mysteries of paleobiology is where complex life (i.e., animals) came from, and what the earliest animals looked like. The first traces of life that we have go back about 3.7 billion years ago, but those are cyanobacteria (the so-called “blue green algae”). The first “true cells”—unicellular eukaryotes, go back to about […]

Another biologist disputes the nature of the tiny “bird/dino” fossil

On March 12, I wrote about the new Nature paper describing the fossil of Oculudentavis khaungraa, identified as a tiny (2-gram) dinosaur/bird found in Burmese amber. But the very next day I had to hedge the results after reading Darren Naish’s Tetrapod Zoology post, not only on humanitarian grounds (the amber used in the study […]

An update on the tiny dino-bird I described yesterday

Yesterday I wrote about the discovery, published in Nature, of a very small theropod dinosaur that appeared to be part of the radiation of early birdlike dinos. It was tiny and had features so unusual that it couldn’t really be placed in a phylogeny. The creature was named Oculudentavis khaungraae and was remarkably well preserved (well, […]

Tiny dinosaur/bird skull found in amber

Yes, we have a novel fossil, just described in Nature, that’s neither fowl nor reptile. And it’s TINY—roughly two grams. How small is it? Well, it’s about the size of the world’s smallest bird: the bee hummingbird of Cuba  (Mellisuga helenae), which is this size: The intermediacy of this fossil, which is part of the […]

“Modern” Homo sapiens may have been in Eurasia as long as 210,000 years ago

The conventional wisdom about the migration of Homo out of Africa, where the genus originated, involves the spread of Homo erectus about 2 million years ago across Eurasia, with that species appearing to have gone extinct without issue. After that, the Neanderthals, which split from the lineage producing “modern” (i.e., living) H. sapiens about 800,000 […]

A 43 million-year-old transitional form: an amphibious whale

The evolution of whales from a small, deer-like artiodactyl took about ten million years: from about 50 million to about 40 million years ago. That’s remarkably fast evolution, especially when you consider the amount of morphological and physiological change that occurred, and the fact that the divergence between chimps and modern humans from their common […]

The earliest known animal?

The Ediacaran fauna, a group of extinct species that lived between 571 and 541 million years ago, has been an evolutionary anomaly. Its fossil record contains multicellular organisms, but they are just plain weird, bearing little resemblance to present-day metazoan (multicellular) animals. The two species of “dickinsoniids” shown below, for example, lack a mouth or […]

How pterosaurs flew

Matthew Cobb called this video to my attention, and I thought it was worth putting up.  Anhanguera is a genus of flying reptile that contains three described species. They were about 1.2 meters tall (four feet) with a 4.5-meter (15-foot) wingspan, and were heavy—weighing about 23 kg (50 pounds). They lived roughly 120 million years […]

Possible life found in sediments between 3.8 and 4.3 billion years old

The Earth is about 4.54 billion years old, and the oldest undisputed life on our planet appears as bacterial “microfossils” 3.5 billion years ago. But because bacteria are already quite complicated organisms, it’s a good bet that life (however you define it), began well before that. But how long? The seas weren’t around much before about […]

The ancestor of deuterostomes? A new report.

A new paper in Nature by Jian Han et al. (reference and free link below; one of the coauthors is Simon Conway Morris, of Burgess Shale fame) describes the earliest known deuterostome: that superphylum of animals in which the blastopore (the first opening into the central part of the embryo) becomes the anus, and the second […]