In a first, scientists spot what may be lungs in an ancient bird fossil

But some paleontologists aren’t convinced the preserved structures are respiratory organs

BY 

CAROLYN GRAMLING 

12:13PM, OCTOBER 19, 2018

ALBUQUERQUE — Fossilized lungs found preserved along with an ancient bird may breathe new life into studies of early avian respiration. If confirmed as lungs, the find marks the first time that researchers have spotted the respiratory organs in a bird fossil.

Scientists have previously described four fossils of Archaeorhynchus spathula, an early beaked and feathered bird that lived about 120 million years ago. But unlike those discoveries, a newly described fifth specimen contains significant traces of plumage, and, even more startling, the probable remnants of a pair of lungs, researchers say.

Vertebrate paleontologist Jingmai O’Connor and colleagues reported the findings October 18 at the Society for Vertebrate Paleontology’s annual meeting. The results were also published online October 18 in the Proceedings of the National Academy of Sciences.

About the size of a thrush, Archaeorhynchus was among the earliest ornithuromorphs, the lineage that led to modern birds. It was probably an herbivore, as all known fossils of the creature contain preserved gastroliths, or gizzard stones which some animals use to help grind food, in the belly. The new fossil was found in northeastern China and is part of the Jehol Biota. That wealth of well-preserved fossils dates to between 133 million and 120 million years ago and includes numerous feathered dinosaurs as well as birds.

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90 million year old bird fossils found in the Arctic

By Helen Clark on 2016-12-24 Science


A new prehistoric species of 90 million years old bird had been identified in the Canadian Arctic, media reports said.

John Tarduno, professor and chair of the Department of Earth and Environmental Sciences at the University of Rochester and leader of the expedition with his team had unearthed three bird bones: part of the ulna and portions of the humerus, which, in birds, are located in the wings. Along with these bones they found the bones of some vertebrates on Axel Heiberg Island in Nunavut, Canada, said CBC News.

From the bone features, as well as its thickness and proportions, the team’s paleontologist, Julia Clarke of the University of Texas, was able to determine the evolutionary relationships of the new birds as well as characteristics that indicate whether it likely was able to fly or dive.

“The bird would have been a cross between a large seagull and a diving bird like a cormorant, but likely had teeth,” said Tarduno.

From the bone features, as well as its thickness and proportions, the team’s paleontologist, Julia Clarke of the University of Texas, was able to determine the evolutionary relationships of the new birds as well as characteristics that indicate whether it likely was able to fly or dive.

These physiological characteristics were still assumptions, Tarduno emphasized, but he said the bird’s environment gives clear indications as to why the bird fossils were found in this location.

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Bird fossil sheds light on how swift and hummingbird flight came to be

posted by news on may 1, 2013 - 5:30am

Durham, NC — A tiny bird fossil discovered in Wyoming offers clues to the precursors of swift and hummingbird wings. The fossil is unusual in having exceptionally well-preserved feathers, which allowed the researchers to reconstruct the size and shape of the bird's wings in ways not possible with bones alone.

Researchers spotted the specimen — the nearly complete skeleton of a bird that would have fit in the palm of your hand and weighed less than an ounce — while working at the Field Museum of Natural History in Chicago.

The newly discovered bird was named Eocypselus rowei, in honor of John W. Rowe, Chairman of the Field Museum's Board of Trustees.

First collected in southwestern Wyoming in a fossil site known as the Green River Formation, E. rowei lived roughly 50 million years ago, after the dinosaurs disappeared but before the earliest humans came to be.

E. rowei was a tiny bird – only twelve centimeters from head to tail. Feathers account for more than half of the bird's total wing length.

To find out where the fossil fit in the bird family tree, the researchers compared the specimen to extinct and modern day species. Their analyses suggest that the bird was an evolutionary precursor to the group that includes today's swifts and hummingbirds.

Given the differences in wing shape between these two closely related groups of birds, scientists have puzzled over how swift and hummingbird flight came to be. Finding fossil relatives like this specimen is key to figuring that out, the researchers say.

Continued: http://www.sciencecodex.com/bird_fossil_sheds_light_on_how_swift_and_hummingbird_flight_came_to_be-111401

Exquisite bird fossils reveal egg-producing ovary

Early avians lost one of two ovaries to take flight.

Brian Switek

17 March 2013

Palaeontologists have discovered the first fossilized traces of developing egg cells in ancient fossil birds, showing a significant trait that already 120 million years ago separate birds from their ancestors. Like modern birds, these ancestors already had reduced their working ovaries to one, setting them apart from their dinosaur cousins.

Zhonghe Zhou, a palaeontologist at the Chinese Academy of Sciences in Beijing, and colleagues studied a fossil specimen of Jeholornis — an early bird that retained archaic characteristics such as a long bony tail — as well as a pair of fossils that belong to the enantiornithines, another extinct group of birds. All three fossils, according to Zhou and co-authors, contain preserved ovarian follicles, delicate structures containing single egg cells that would have developed into eggs. The researchers present their findings online today in Nature.

 “It took us a while to figure out what these strange circular structures actually represent,” says Zhou. The small structures might possibly have been seeds or tiny stones the birds had swallowed to grind food in their digestive system. But on the basis of the size, shape, and position of the rounded structures, the team ruled out the alternative explanations and interpreted them as ovarian follicles.

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http://www.nature.com/news/exquisite-bird-fossils-reveal-egg-producing-ovary-1.12616