Posts

Everett Olson and His Contribution to the Mass Extinction Narrative.

Image
Greetings. Olson's Extinction, named after paleontologist Everett C. Olson, was a mass extinction that occurred approximately 273 million years ago during the Late Permian period. The extinction predated the monumental Permian/Triassic extinction event by a few million years.  Olson first identified a substantial gap in fossil record strongly indicating an abrupt change between the early Permian and middle/late Permian faunas. This event has been argued by many paleontologists to have affected many taxa, including embryophytes, marine metazoans, and tetrapods. The first signs that indicated extinction came to light when Olson noted a hiatus between early Permian faunas dominated by pelycosaurs and the therapsid-dominated faunas of the middle and late Permian. Initially taken to be a preservational gap in the fossil record, the event was originally dubbed "Olson's Gap." To compound the difficulty in identifying the cause of the "gap," paleontologists had diff...

A Gorgeous Little Theropod.

Image
Greetings. Allosaurus. Carnotaurus. Spinosaurus. Velociraptor. The iconic Tyrannosaurus rex. Theropods all. Included in that particular group of animals are all birds, avian dinosaurs numbering about 11,000 living species today. One particularly beautiful living example is Pharomachrus mocinno.  The resplendent quetzal, Pharomachrus mocinno, is a small bird found in Central America and southern Mexico that lives in tropical forests, in particular montane cloud forests. A member of the family Trogonidae, the resplendent is for the most part omnivorous; its diet mainly consisting of the fruits of plants in the laurel family, occasionally preying on insects, lizards, frogs and snails. Pharomachrus mocinno possesses a colorful and complex plumage that differs substantially between the sexes. Males have iridescent green plumes, a red lower breast and belly, black innerwings, and a white undertail. Females have grey lower breasts, bellies, and bills, along with bronze-green heads, and sh...

A Miocene Species, Extant, Advanced & Prehistoric.

Image
Greetings. The hoatzin, Opisthocomus hoazin, is a species of tropical avian dinosaur that arose in the Miocene approximately 23 million years ago, a native of the Amazon and Orinoco river basins of South America.  The only extant species of the ancient genus Opisthocomus, the hoatzin occupies swamps, mangroves, and other tropical forest habitats. The species has been successful since it first appeared in the fossil record, and has several contradictory physical characteristics that confirm its ancient lineage, yet suggest advanced evolutionary processes at work. The young of the species possess claws on two of its wing digits, unique to modern birds, and reminiscent of Jurassic and Cretaceous Period birds. Adults have digestive systems that are capable of fermentation and the processing of plant matter, two attributes known from some primates and herbivorous ungulate mammals, but not known from any other species of modern bird.  Hoatzins have a length of about 65 centimeters, ...