Friday, October 26, 2018

48-Million-Year-Old Fossil Owl Is Almost Perfectly Preserved

Live Science Animals

48-Million-Year-Old Fossil Owl Is Almost Perfectly Preserved

By Laura Geggel, Senior Writer | October 23, 2018 


ALBUQUERQUE, N.M. — About 48 million years ago, an owl swooped down to catch its prey, not by the light of the moon but in broad daylight.

How do paleontologists know this fowl wasn't a night owl? They found the exquisitely preserved remains of an owl, and its skull shares a telltale characteristic with modern-day hawks, which also hunt by day, the researchers said.

The finding is extraordinary, largely because it's rare to find fossilized owls, especially one that has so many preserved bones, said project co-researcher Elizabeth Freedman Fowler, an assistant professor at Dickinson State University in North Dakota, who dubbed the specimen "the finest fossil owl."

"There is no fossil owl with a skull like this," Freedman Fowler told Live Science. "Bird skulls are incredibly thin and fragile, so to have one preserved still in three dimensions, even if slightly crushed, it's amazing. It even has the hyoids at the bottom, the bones that attach to the tongue muscles."

The skull is in such good shape that the researchers noticed that the supraorbital processes (the regions above the eye sockets) have a bony overhang, making it look as if the owl had a mini baseball cap on top of each eye, according to the research, which was presented here at the 78th annual meeting of the Society of Vertebrate Paleontology on Oct. 19. The study has yet to be published in a peer-reviewed journal.

This overhang "gives you shade so you don't get dazzled [by the sun]," said project lead research Denver Fowler, a curator of paleontology at the Badlands Dinosaur Museum in North Dakota. This feature is weak or absent in nocturnal owls, but it's common in modern hawks and daytime owls, he noted.

The finding isn't completely out of the blue. Birds are diurnal — or daytime — creatures, and at some evolutionary point, the owl changed course and became nocturnal, he said. What's more, there are diurnal owls alive today, including the northern hawk owl (Surnia ulula) and the northern pygmy owl (Glaucidium gnoma), Marc Devokaitis, a public information specialist at the Cornell Lab of Ornithology in Ithaca, New York, previously told Live Science.

What's unclear is whether this mysterious specimen was an early form of owl that hunted during the day, before most owls became nocturnal, or whether it was an owl outlier that hunted during the daytime while other owl species stalked prey by night, Fowler told Live Science.

In all, the researchers have about 45 percent of the owl's skeleton, including the skull and bones from the legs, feet, wings and lower jaw. That's way more material than what has been found with other discoveries of fossilized owls — some of which are given scientific names based on a single fragment of a bone, Freedman Fowler said.

The owl was discovered by project co-researcher John Alexander, a research associate at the Burke Museum of Natural History and Culture at the University of Washington, while he was digging for fossils of ancient lemur-like animals known as Notharctus and Smilodectes in the Bridger Formation of southwestern Wyoming in 2007. Given that he was looking for mammals, he said he was surprised to find a bird of prey.

"This is the first predatory bird skeleton found in that formation, and people have been looking in there for 150 years," Alexander told Live Science.

However, it wasn't until recently, after showing the specimen to Fowler, that Alexander realized the specimen was an owl — one a little larger than a modern barn owl (Tyto alba).

It's not yet clear whether the owl is a newfound species, or whether it's already known in the scientific literature, but only from a fragment, Freedman Fowler said. But they expect to find out soon, as well as learn as much as they can about the ancient hunter.

"We just CT [computed tomography] scanned this, so we'll get the results back from that soon," Freedman Fowler said. "We can look at things like neck mobility — we have the cervical vertebrae, so we can see how far it could move its neck."

In addition, the braincase (the inner part of the skull that held the owl's brain) is well-preserved, "so we'll be looking at the different parts of the brain to see what its senses were like, [including] how well it could hear and how well it could see," she said.

This wasn't the only owl finding presented at the conference. Peter Houde, a professor of biology at New Mexico State University, found bones from two different owl species in the Clarkforkian-Wasatchian beds of north-central Wyoming, one dating to about 56 million and the other to about 55 million years ago. That's a bit younger than Ogygoptynx, the oldest owl on record, which lived in what is now Colorado about 61 million years ago, just a few million years after the nonavian dinosaurs went extinct about 65 million years ago, Houde told Live Science.

Monday, October 22, 2018

First fossil lungs found in dinosaur-era bird

Preserved for 120 million years, the organs offer fresh perspective on the origins of avian flight.

From National Geographic

By Michael Greshko

Published October 22, 2018

Image courtesy of J. Zhang, Institute of Vertebrate Paleontology and Paleoanthropology

About 120 million years ago in what’s now northeastern China, a bird met its end during a volcanic eruption. Ashfall buried the animal so suddenly, its soft tissues didn’t have time to decay, and over millions of years, minerals infiltrated these tissues and preserved their form.

Now, researchers have unveiled this breathtaking specimen, which contains the first fossilized lungs ever found in an early bird.

The species Archaeorhynchus spathula lived alongside the nonavian dinosaurs during the Cretaceous period. The newfound fossil, which preserves feathers and considerable soft tissue, shows that this primitive bird's lungs closely resemble those found in living birds. This suggests that birds’ hyper-efficient lungs, a key adaptation for flight, first emerged earlier than thought, and it underscores how birds—the last living dinosaurs—inherited many iconic traits from their extinct ancestors.

“Everything we knew about lungs, about respiration, about evolution of [birds] was just inferring based on skeletal indicators," says study coauthor Jingmai O’Connor, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China. "And now we know that we were inferring less generously than we should have.”

O’Connor presented the discovery on October 18 at the Society of Vertebrate Paleontology’s annual meeting in Albuquerque, New Mexico, and the finding will be published in the Proceedings of the National Academy of Sciences.

“This is an exciting discovery,” says Colleen Farmer, an anatomist and physiologist at the University of Utah who reviewed the study. “Finding bird-like lungs in this group of dinosaurs is to be expected, but it is incredible to uncover hard evidence of this soft structure.”

Fossilization itself is rare, and rarer still are fossils that preserve traces of soft tissue. So far, researchers have found ancient fish with fossilized hearts and armored dinosaurs with pebbly skin. O’Connor herself has found ovarian follicles—the sacs that hold unfertilized eggs—in dinosaur-era birds. And three earlier studies have described bits and pieces of fossilized lung.

Having the lungs of a fossil bird is exceptionally handy, though, when you’re trying to reconstruct how birds evolved into such effective fliers.

Lungs work by exchanging oxygen and CO2 across a thin membrane full of blood vessels. The bigger and thinner this membrane is, the more efficient—and intricately folded—the lungs become. In some people, the inner surfaces of their lungs add up to more than 500 square feet.

Since powered flight is a brutal workout, birds take their lungs to the extreme. They have such highly subdivided lungs, the tissues curl around their ribcages for support. Unlike in other animals, bird lungs don’t expand and contract. Instead, they’re connected to a series of separate air sacs that sit beneath the lungs and act as bellows. These adaptations, Farmer says, let the lung membranes get exceptionally thin—which makes them exceptionally efficient at absorbing oxygen, all the better for nourishing flight muscles. But when did these specialized lungs evolve?

Initially, O’Connor and her colleagues at China’s Shandong Tianyu Museum of Nature weren’t looking to figure out this respiratory riddle. Instead, they were interested in the fossil because it was the first that preserved A. spathula’s plumage, including its ornamental tail feathers—the first ever found in this group of extinct birds.

But as O’Connor and her colleague Xiaoli Wang examined the fossil, they noticed two unusual mats of white speckled material in the bird’s torso. The structures formed two distinct lobes in the animal’s chest, a sign that they might be fossilized lungs.

When the researchers initially wrote up a description of the fossil, they focused on the feathers, mentioning the possible lungs only in passing. According to O’Connor, their initial study was rejected after one reviewer lamented that the team hadn’t definitively proven the structures were lungs.

In response, O’Connor and Wang decided to analyze the potential lungs in greater detail. Using powerful microscopes, the team revealed honeycombs of tiny voids less than a tenth of the width of a human hair. To make sense of these voids, O’Connor emailed University of Johannesburg professor John Maina, an expert on birds’ lung anatomy. Maina, who is one of the final study’s coauthors, replied that the structures looked like the finely subdivided inner chambers of a bird’s lungs. The microscopes even showed individual air channels.

“They rejected me … and I was like, bone wars!” jokes O’Connor, referring to a period of intensely competitive fossil hunting in the 1800s. “So, then I went and [examined] it, and I was like, boom! Lung tissue.”

Other experts agree that O’Connor and her colleagues make a strong case that the structures are lungs.

“More will need to be done to confirm this identity, but it looks very promising to me,” says University of Southern California paleontologist Mike Habib, an expert on the biomechanics of flying animals such as early birds.

Many questions remain, however, such as how the lungs fossilized in the first place. University of South Florida paleontologist Ryan Carney, an expert on the feathered dinosaur Archaeopteryx, suggested one possible explanation in an email: “One hypothesis is that this potential lung preservation—and possibly the unusual, ‘speckled white material’ itself—was due to the bird's inhalation of volcanic ash.”

In the meantime, O’Connor stresses the importance of studying fossils’ soft tissues whenever possible, since they can reveal features that bones simply can’t record.

“A theme that's come up within paleontology the last five years is that when we learn about the soft tissues … we see that the skeleton always lags behind in the evolution of specialization,” she says. “When we’re just studying the skeleton, we’re basically being conservative.”

Monday, October 15, 2018

The Avian Tibiotarsus; its length can tell us a lot about a birds behavior.

The bones of the avian leg are laid out in a fairly regular pattern, the femur, tibia and fibula, and the tarsometatarsus. The bird’s tibia has been fused with some of the upper bones of the foot to form the tibiotarsus. A small toothpick-like remnant of the fibula parallels the tibiotarsus along its length. 

From Avian Osteology; Gilbert, Martin, Savage. 1996
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Whether it’s looking at a diagram of a bird skeleton, or picking through a pile of dried bird bones, the tibiotarsus is often overlooked as the go-between, linking two of the more familiar leg bones. Let’s see what we can do about changing this misconception.
   
From Manual of Ornithology; by Proctor N.S. 1993
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
One of the things I notice most about birds is how often they revert back to their terrestrial roots. Despite their unique ability to fly and perch in trees, almost every bird, at some point of the day, will find their feet planted squarely on the ground.

How they carry themselves from here can tell us a lot about their daily behavior. Are they like the Dark-eyed Junco (Junco hyemalis), which hop about circling in a somewhat confined area? Or do they methodically walk across expansive lawns searching for food like the American Crow (Corvus brachyrhynchos)?

More surprising are the terrestrial habits of the Gray Catbird (Dumetella carolinensis). It too can fly long distances; however, catbirds prefer to instead spend most of their time running through the underbrush chasing insects.

Gray Catbird (Dumetella carolinensis)
Image Property of feederwatch.org
https://avianmusing.blogspot.com/
Not much is often made of the catbirds running capabilities, but one website interestingly mentions its wings and wing musculatures having experienced a decrease in development; by which its terrestrial habitats have led to a corresponding improvement in its running ability (source; beautyofbirds).

Should this adaptation for running be detected in the catbirds skeletal structure? The answer to this question is yes.

The Gray Catbird shows a dramatic difference in ratio between the femur and tibiotarsus. A shorter femur meant that each leg was able to cycle faster through each rotation. A longer tibia/fibula reaches farther with each step. 

Gray Catbird (Dumatella carolinensis) femur and tibiotarsus
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Red-tailed Hawk (Buteo jamaicensis) femur and tibiotarsus
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Paleontologist use this same femur/tibiotarsus length ratio to determine the speed of some dinosaurs. The highly cursorial ornithomimosaurs were a group of ostrich-like dinosaurs that must have had a similar lifestyle (source; Dinosaurs. A Concise Natural History. 2016. Fastovsky and Weishampel). 

From Dinosaurs. A Concise Natural History by Fastovsky and Weishampel. 2016
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
The tibiotarsus is also important to leg musculature. The tibialis anterior is a muscle that covers the anterior surface of the leg along the tibiotarsus, originating on the distal end of the femur and inserting on the proximal tarsometatarsus. The tibialis flexes the tarsometatarsus forward, helping the bird lift its foot off the ground (source; Manual of Ornithology. Proctor, N.S.). 

From Manual of Ornithology; Proctor N.S. 1993
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Another muscle that controls the thigh and leg is the ambiens. The ambiens attaches to the ilium and pubis; making its way down through the knee tendons to its insertion at the top of the tibiotarsus.

Monday, October 8, 2018

THEM: Age Of Dinosaurs. A Pictorial Book Review.

When is a dinosaur book considered too big? The answer to this question is, “when its unable to fit on any of your custom made library shelves”.

However, with regards to today’s pictorial book review, the answer may very well be; “a dinosaur book can never be too big”.  

“THEM: Age of Dinosaurs - A Science Art World book by ZHAO Chuang and YANG Yang” is a themed exhibition based on works by the two founders of PNSO and produced by Yiniao Sci-Art.

THEM: Age Of Dinosaurs, by ZHAO Chuang
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Originally known from their production of dinosaur figures, PNSO is certainly an up and coming name in bringing life to many of today’s significant fossil discoveries.

From working with paleontologists from across the globe, to hosting major dinosaur exhibitions, Chinese artist ZHAO Chuang has gained a well reputation for accuracy and insight.

Published in 2015, THEM: Age of Dinosaurs, is a celebration of ZHAO Chuang’s artwork, which brilliantly captures a time when dinosaurs ruled the earth.

A 239-page hardcover book measuring 14x11 inches, THEM: Age of Dinosaurs offers the reader a unique opportunity to closely study the artists handiwork in a larger than life format.

ZHAO Chuang’s talents as an artist is on full display in this book, mixing highly detailed subjects with slightly passive backgrounds, creating a three-dimensional look to much of his artwork. 

THEM: Age Of Dinosaurs, by ZHAO Chuang
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
I also enjoyed his use of darkened backgrounds, with shadows and light, which is incredibly exhibited in the theropod Indosuchus, shown peacefully resting on its haunches. Along the same lines, and equally impressive, is a nighttime hunting Dilong. 

THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Detail is where ZHAO Chuang excels, and in his painting of Yi, it is hard to imagine a better visual of such a strange and special creature. The underside of the wing membrane structure is remarkable. 

THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Selling this book and ZHAO Chuang’s art to the masses is easy when one set eyes on his rendition of Yutyrannus and pack-hunting Sinornithosaurus. Convincing in so many ways. 

THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Oddly enough, the image that moved me the most in this impressive book is the painting of Epidendrosaurus. Simply placed clinging to a small tree sapling, one can sense a feeling of both fear and fearlessness throughout this animal’s entire body. A moonlit sky reflects off a large eye, implying nighttime feeding habits. 

THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
ZHAO Chuang also provides some diverse artistic styles in this coffee-table sized book. His version of Luoyanggia and Yunmenglong makes you wonder how the same artist could have painted the head profile of Carnotaurus a few pages earlier. It still boggles my mind! 

THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
One of the most mysterious images of THEM: Age of Dinosaurs, is found on page 210 featuring Qianzhousaurus, a tyrannosaur. Describing it is difficult, appearing as a collage of different art mediums; from paint and digital photography, to 3D computer graphics for sculpture. Maybe I’m wrong, but nowhere else in this book do you find a style of artwork designed quite like this one. 

THEM: Age Of Dinosaurs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
The accompanying text to the artwork is provided by fairy tale writer YANG Yang. Fanciful in every way, YANG Yang’s short stories place thoughts and emotion into each and every dinosaur illustration. Odd however is the idea that many of the wandering creatures were outwardly described as lonely and yearning for a friend. To be fair, this must be a cultural thing, hard for some westerners to actually understand.    

So, if you are a person who loves paleoart, or collects really cool dinosaur figures, especially feathered ones, this book is a gift and nod to you. Enjoy!

Monday, October 1, 2018

Rufous-winged Ground-Cuckoo (Neomorphus rufipennis). All Birds Considered

All Birds Considered Doc. for BLOG

Inspired by David Attenborough’s book, The Life of Birds, is a monthly spin-off segment of my blog called “All Birds Considered”, which I hope will bring attention to some of the more unusual, and lesser known birds of our world.

The Life Of Birds by David Attenborough
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/

Species; Rufous-winged Ground-Cuckoo (Neomorphus rufipennis)

Introduction; This mysterious species was first described more than 150 years ago from one specimen collected on the lower Orinoco River in Venezuela; since that time, we have garnered virtually no additional knowledge on the life history of Rufous-winged Ground-Cuckoo. For example, the assumption that the species is not brood parasitic (as are many other cuckoo species) is based on a single observation of a young bird accompanied by its parents while they foraged on an anthill. Rufous-winged Ground-Cuckoo is often wary of intruders and, as such, it may be difficult to observe as it runs swiftly along the forest floor. It can be most easily detected by its loud single-noted hooting vocalization, which is somewhat dove-like in nature, and its distinctive bill-snapping. Rufous-winged Ground-Cuckoo occurs at low density in the tropical lowland forest of northern Amazonia, from eastern Colombia to southern Venezuela, Guyana, and the northern tip of Brazil in the state of Roraima.

Rufous-winged Ground-Cuckoo (Neomorphus rufipennis)
Image Credit: Neotropical Birds, Cornell University
https://avianmusing.blogspot.com/
Description; The adults are about 50 cm (20 in) in length. They typically have a semi-shiny dark-green feather on the back. The crest is a glossy black with a purple-undertones. Its throat is ash-white to gray but some have been seen with black coloring. Its wings are dark red and the belly is distinctly scaled

Voice; The territorial call of the Rufous-winged Ground-Cuckoo is a loud forceful whOOu (Hilty 2003) with a frequency of 0.8-0.9 kHz that lasts about 0.3 sec (Hardy et al. 1990). The call has a dove-like quality (e.g., Blue Ground-Dove, Claravis pretiosa; Haffer 1977), but is clearer, louder, and more far-ranging (Zimmer and Hilty 1997, Hilty 2003). Rufous-winged Ground-Cuckoos may give their call when walking on the forest floor or when perched 0.5-3 m up on a tree branch or log. The maximum calling rate is typically about once every 5-10 seconds for up to several minutes (Hilty 2003).

Rufous-winged Ground-Cuckoo (Neomorphus rufipennis)
Image Property Of: Wikipedia
https://avianmusing.blogspot.com/
Behavior; Rufous-winged Ground-Cuckoo is primarily terrestrial; although, they are capable of rapid flight, particularly when startled (Meyer de Schauensee and Phelps 1978, Hilty 2003). It has been described as solitary, restless, wary, and difficult to see (Meyer de Schauensee and Phelps 1978); however, it may be approached very closely on occasion (Hilty 2003).

Rufous-winged Ground-Cuckoo usually is seen walking or running swiftly along the forest floor in pursuit of prey. When pausing, they may raise their slightly spread tail somewhat above the horizontal. They also hop into low vegetation or perch on branches a meter or so up in the understory (Haffer 1977).

Rufous-winged Ground-Cuckoo (Neomorphus rufipennis)
Image Property Of: Macaulay Library
https://avianmusing.blogspot.com/
Habitat; Rufous-winged Ground-Cuckoo occupies tropical lowland evergreen forest (Parker et al. 1996) and upland terra firma forest (Zimmer and Hilty 1997); it sometimes also occurs in seasonally-flooded (várzea) forest in Venezuela (Erritzöe et al. 2012). Prefers foothill zone of mountains from 100 to 1100 m (Meyer de Schauensee and Phelps 1978, Parker et al. 1996, Hilty 2003). It is found primarily in undisturbed forest but can be observed rarely in disturbed forest in the Iwokrama Forest Reserve, Guyana (Ridgley et al. 2005).

Conservation and population; The population has not been recorded. Because the bird has a very wide habitat and range, it is not considered vulnerable. Even though its population is estimated to be trending downward. It is expected to decline less than 25% over the next 13 years. It is a restless and solitary bird that spends a majority of its time running along the ground.

Source:

https://neotropical.birds.cornell.edu

Wikipedia

The Life of Birds by David Attenborough, 1998.

Birds of Southern South America and Antarctica. 1998. Martin R. DE LA Pena and Maurice Rumboll