Thursday, February 28, 2019

Quill knobs; on a carpometacarpus?

“Believe nothing you hear, and only one half that you see.” A quote from the great American poet and author Edgar Allan Poe.

I couldn’t help but to think back to those exact words the other morning while reading Sankar Chatterjee’s book; The Rise of Birds, 225 Million Years of Evolution (2015).

Here, Chatterjee nicely illustrates (and labels) the anatomical similarities and differences between forelimbs of a dromaeosaur (Deinonychus), and a Golden Eagle (Aquila chrysaetos). 

Dromaeosaur and Golden Eagle (Aquila chrysaetos) forelimb comparisons
Image from: Rise of Birds by Sankar Chatterjee (2016)
https://avianmusing.blogspot.com/
Informative in so many ways, the diagram did however present one peculiar and curious detail. Highlighted on the carpometacarpus of the Golden Eagle were six conspicuously drawn quill knobs. Quill knobs, I questioned, on a carpometacarpus? Have I ever seen quill knobs on a carpometacarpus before?

Golden Eagle (Aquila chrysaetos) carpometacarpus 
Image from: The Rise of Birds by Sankar Chatterjee (2016)
https://avianmusing.blogspot.com/
Quill knobs are typically shown on the ulna, where they serve as attachment points where secondary flight feathers are affixed to the bone with ligaments.

Northern Flicker (Colaptes auratus) ulna quill knobs
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Taking Poe’s words to heart, I started to second guess my own knowledge of avian wing topography. Was I just plain careless over the years to have missed such an obvious feature? Or, was Chatterjee’s illustration a gross exaggeration.

As soon as I arrived home that evening, I pulled out a few (sixteen to be exact) bird bone specimens, systematically examining each and every one. What I discovered under the microscope was that most of the carpometacarpus’s lacked quill knobs altogether, with one bone holding a potential attachment point.

The carpometacarpus is unique to birds. It is the result of fusion of carpals and metacarpals. A carpometacarpus is reminiscent of a violin bow. The grip is composed of metacarpal I and has a pronounced pisiform process in the middle of its palmar surface and a metacarpal process extending radially. The bow is metacarpal II, and the much thinner metacarpal III represents the strings (source: Avian Osteology. Gilbert, Martin, Savage.1996).

Avian carpometacarpus
Image from: Avian Osteology, Gilbert, Martin, Savage. (1996)
https://avianmusing.blogspot.com/
Equally confusing is how the carpometacarpus is depicted in print while supporting most of the primary remiges. Some Ornithology manuals place the primary attachment directly on the slimmer metacarpal III, with the feather quills held firmly in place by the postpatagium. 

Rock Dove (Columba livia) wing anatomy
Image from; Manual of Ornithology, N.S. Proctor (1993)
https://avianmusing.blogspot.com/
Others, including a recent research paper (2016) on the flight feather attachment in rock pigeons, clearly shows the primaries attaching onto metacarpal II of the carpometacarpus. 
https://www.researchgate.net/publication/304192129

Carpometacarpus primary feather attachments
Image from; Tobin L. Heironymus

So, who do we believe here? Where do the primaries actually attach? Is Chatterjee’s illustration correct? If so, where are all the quill knobs?

As I had mentioned earlier, I did detect what looks to be an attachment scar on metacarpal II of the carpometacarpus on a Pleistocene-aged American Coot (Fulica Americana). 

Possible American Coot (Fulica americana) carpometacarpus quill scar
Photo Credit: Paul Cianfaglione
 https://avianmusing.blogspot.com/
If quill knobs did exist on the carpometacarpus, it makes more sense that they would be found on the wider and stronger metacarpal II. Chatterjee’s placement of the quill knobs (on metacarpal II) would therefore be correct, but to what extent.

After examining sixteen specimens myself, I still dispute the idea that quill knobs on a birds carpometacarpus are clear or apparent. Specimens that I inspected ranged in size from the large bodied Southern Screamer (Chauna torquata) and American Crow (Corvus brachyrhynchos), to the diminutive wood warblers and sparrows.

American Crow (Corvus brachyrhynchus), Northern Flicker (Colaptes auratus), American Coot (Fulica Americana)
carpometacarpus's (from top to bottom)
Photo Credit: Paul Cianfaglione
 https://avianmusing.blogspot.com/
Granted, sixteen specimens does not qualify me as an expert on this subject, nor prove anything either way. Maybe Golden Eagles, and other species, do have prominent quill knobs on their carpometacarpus. At this moment, I wouldn’t know.

My hope is to see more illustrations, like the one below, that show the correct position of the primaries in relation to the carpometacarpus.

Bird wing feather attachments
Image from; Tobin L. Heironymus


Tuesday, February 19, 2019

Avian Hypoglossal Nerve

The Blue Jay (Cyanocitta cristata) is a common bird of urban areas and rural farms throughout most of eastern North America. Unlike the Northern Flicker (Colaptes auratus), the jay is an avian generalist, with a sturdy but anatomically unremarkable body suited to exploit a wide variety of habitats and food sources.

Northern Flicker (Colaptes auratus)
Image Property of Audubon.org
https://avianmusing.blogspot.com/
Despite both being relatively the same size, it was interesting to be able to compare the contrasting forms and function of their skeletal structures. The most distinguishing feature to me was in the shape of their skulls and bills.

Blue Jay (Cyanocitta cristata) left, and Northern Flicker (Colaptes auratus) skulls
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
The feeding strategies of these superficially similar species places them in unique ecological niches.

In the hand, and side-by-side, the Northern Flickers skull has a noticeably longer bill, which it uses to hammer in the soil searching for ants. Flickers have a remarkable protractible tongue, derived by great elongation of the basihyal and part of the hyoid horns, that is characteristic of woodpeckers. The sticky tongue darts out as much as 4 cm beyond the bill tip as it laps up adult and larval ants (source: Birds of North America Online).

As a generalist, the Blue Jay uses its nicely proportional bill to feed on arthropods, acorns and other nuts, soft fruits, seeds, bird eggs, and small vertebrates, which it does so in trees and shrubs, and on the ground.

But I also noticed one other feature while I was looking at the Blue Jays skull under the microscope. Located toward the rear of the skull, near the foramen magnum, were a series of symmetrically placed holes (canals) perforating the skull. I thought, what purpose do these holes serve? 

Blue Jay (Cyanocitta cristata) skull foramen
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Blue Jay (Cyanocitta cristata) skull foramen
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
According to the Handbook of Avian Anatomy (Baumel & Witmer), the holes on either side of the occipital condyle represent the exit points for two nerves, the vagus nerve and the hypoglossal nerve. Although difficult to discern, and contrary to the Manual of Ornithology (Proctor N.S. 1993.), I believe the hypoglossal canals are the smaller holes closest to the occipital condyle. 

Handbook of Avian Anatomy/Baumel & Witmer
https://avianmusing.blogspot.com/
Bird Anatomy/Wikisource
https://avianmusing.blogspot.com/
Manual of Ornithology/Proctor N.S. 1993
https://avianmusing.blogspot.com/
The hypoglossal nerve is the twelfth cranial nerve, and innervates all the extrinsic and intrinsic muscles of the tongue, except for the palatoglossus which is innervated by the vagus nerve. It is a nerve with a solely motor function. The nerve arises from the hypoglossal nucleus in the brain stem as a number of small rootlets, passes through the hypoglossal canal and down through the neck, and eventually passes up again over the tongue muscles it supplies into the tongue. There are two hypoglossal nerves in the body: one on the left, and one on the right (source: Wkipedia).

This was very interesting. Given its daily dependence on its abnormally long tongue, one would think that the Northern Flicker should show dramatically larger hypoglossal canals (larger nerves) than the similarly sized Blue Jay. Unfortunately, this is not the case. The flicker and jay hypoglossal canals appear equal in size.

Northern Flicker (Colaptes auratus) skull foramen
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
Northern Flicker (Colaptes auratus) skull foramen
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
The size of the hypoglossal canals has also been considered in other animals;

The size of the hypoglossal nerve, as measured by the size of the hypoglossal canal, has been hypothesized to be associated with the progress of evolution of primates, with reasoning that larger nerves would be associated with improvements in speech associated with evolutionary changes. This hypothesis has been refuted (source: Wikipedia).

Sunday, February 17, 2019

The Color of Grouse. Avian Darwin.

The Color of Grouse. Avian Darwin. 


Passage;

“Although natural selection can act only through and for the good of each being, yet characters and structures, which we are apt to consider as of very trifling importance, may thus be acted on. When we see-eating insects green, and bark-feeders mottled-grey; the alpine ptarmigan white in winter, the red-grouse the color of heather, we must believe that these tints are of service to these birds and insects in preserving them from danger. Grouse, if not destroyed at some period of their lives, would increase in countless numbers; they are known to suffer largely from birds of prey; and hawks are guided by their eyesight to their prey-so much so, that on parts of the Continent persons are warned not to keep white pigeons, as being the most liable to destruction. Hence natural selection might be effective in giving the proper color to each kind of grouse, and in keeping that color, when once acquired, true and constant. 

Charles Darwin

Origin of Species; 1873.

Chapter 4, page 66, Natural Selection.

First edition in which Darwin uses the word evolution. This was also the last edition published during Darwin's lifetime.

Friday, February 15, 2019

Pre-modern Birds: Avian Divergences in the Mesozoic. A Brief Summary.

Before delving into any new book or research paper on the evolution of birds, it would help to first briefly review some well-written, easy to comprehend summaries. I have provided below one of my favorite abstracts (conclusion) from the research paper; Pre-modern Birds: Avian Divergences in the Mesozoic, by Jingmai O’Connor, Luis Chiappe and Alyssa Bell. The entire article is conveniently found in the book; Living Dinosaurs, The Evolutionary History of Modern Birds, edited by Gareth Dyke and Gary Kaiser (2011), a compilation of seventeen scientific papers. 

Living Dinosaurs. The Evolutionary History of Modern Birds
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/

Pre-modern Birds: Avian Divergences in the Mesozoic.

When taxa are placed in the frame of phylogenetic hypothesis, the Mesozoic avian fossil record reveals several interesting hypotheses regarding early evolutionary trajectories. Avian evolution is highly plastic and numerous characters and ecomorphs acquired during the Cenozoic evolution of Neornithes had already been experimented with by multiple lineages of Mesozoic birds. For example, the absence of teeth, a synapomorphy for Neornithes, evolved in several lineages of Mesozoic, pre-modern birds (e.g. Confuciusornithidae, Gobipteryx) as well as outside Aves within Theropoda. The postorbital bone likely reduced several times outside Ornithuromorpha where it was lost, and the diapsid condition appears secondarily derived within the Confuciusornithids and at least one enantiornithine. Manual reduction also shows convergent reduction within Enantiornithes and Ornithuromorpha although the manus of each group is distinct morphologically from the other. Ecologically, the Mesozoic radiation of birds also achieved and thus pre-dated some of the specializations seen among their living counterparts. For example, flight-lessness, typical of numerous lineages of modern birds, is inferred to have evolved independently in at least three lineages of Mesozoic birds (i.e. Patagopteryx, Hesperornithiforms, and possibly in the enantiornithine Elsornis). Littoral ecomorphs evolved in the form of wading birds in both clades of ornithothoracines (Lectavis and the hongshanornithids) as well as in the form of trophically specialized mud-probing taxa Longirostravis and Rapaxavis (enantiornithines). The flightless hesperornithiforms were highly specialized divers, similar in appearance to the modern grebes, with dense bones and rotating lobed feet. 

Rapaxavis pani
Image Credit: Wikipedia
https://avianmusing.blogspot.com/ 
The Late Jurassic Archaeopteryx continues to be the oldest and most primitive known bird. By around 130-120 Ma, a large number of lineages make their debut in the fossil record in the now celebrated sediments of the Jehol Group in northeastern China. No information, however, is available for the roughly 20 million-year-gap between when Archaeopteryx lived and when the Jehol avifauna flourished. Undoubtedly, this time period holds critical clues for understanding the early phases of avian diversification in the Mesozoic. The Jehol avifauna provides an excellent picture of avian diversification in the Early Cretaceous. A number of long-tailed birds, whose precise taxonomy and relationships need to be further studied, are recorded alongside early pygostylians (short-tailed birds) and ornithothoracines (enantiornithines and ornithuromorphs). With the exception pf the insular Rahonavis, which some interpret as non-avian, all pre-ornithothoracine birds disappear from the fossil record after the time recorded by the Jehol avifauna. Later in the Early Cretaceous, both enantiornithines and ornithuromorphs diversified across the globe. Throughout the Cretaceous Period these birds occupied a wide variety of marine, shoreline, and continental habitats using a diversity of morphological features. Early in their divergence, these birds established themselves as strong flyers, possessing skeletal (i.e. narrow furcula, keel) and integumentary modifications for flight (i.e. alula, tail fan). Nested within the ornithuromorph radiation is the radiation of modern birds. The fossil record indicates that this radiation was well established by the close of the Cretaceous although the timing and sequence of this diversification is still unclear.

The inferred evolutionary relationships between pre-modern birds continue to change as new lineages are discovered and new data becomes available for known taxa. The incredible diversity now known reflects a large amount of new morphological information that is not currently reflected in publications. Detailed studies of these fascinating new birds will lend greater detail to our understanding of the earliest avifaunas.    

Wednesday, February 13, 2019

Panama Fruit Feeder Camera

Panama Fruit Feeder Camera

Lights, camera, action! Keep an eye on the Canopy Tower feeder camera day and night for these Panama birds and animals. 

Canopy Tower Fruit Feeder Camera
https://avianmusing.blogspot.com/

Thursday, February 7, 2019

Avian Uncinate Process

In comparison to other vertebrates such as reptiles and mammals, the avian skeleton shows extensive fusion of bones into rigid structures that are both lightweight and strong enough to hold up to the severities of flight. The most distinctive of skeletal adaptations are found in the thorax and pelvis.

In the thorax, the thoracic vertebrate is tightly bound in a rigid structure that resists twisting and bending forces associated with wing flapping. The individual ribs of flying birds have a unique structure of backward-pointing bony extensions called the uncinate process. These small extensions are lateral braces that attach the ribs to each other in addition to the attachments to the spine and sternum, forming a strong supporting “basket” around the lungs and heart (source: Manual of Ornithology, Proctor N.S. 1993.).

American Goldfinch (Spinus Tristis) Uncinate Process
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
The uncinate processes are functionally linked to movements of the vertebral ribs and sternum during breathing; acting as a lever arm for movement of the ribs in a fixed plane about their articulation on the vertebral column (source; Codd J.R. 2004).

Given the demands of flight, it is not too hard to imagine how an evolutionary trait like the uncinate process could transpire in modern day birds. 

Mallard (Anas platyrhynchos) Uncinate Process
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
American Crow (Corvus brachyrhynchos) Uncinate Process
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/
What I don’t quite understand is why bony extensions would have evolved on the ribs of 120 million-year-old fossil oviraptorids and basal birds, many of which possessed questionable flight capabilities.

Did the uncinate process develop in bipedal non-avian dinosaurs and early birds to help assist in dynamic breathing during the inception of forearm-flapping or running? That is a good question. 

The fossils also reveal a puzzling feature to the process that is often mentioned, but rarely given further details.

If we look closely at the fossil images, we will notice that the processes are not actually ossified to the ribs, and may have been attached by cartilage or ligaments instead. 


Confuciusornis Uncinate Process
Image Credit: Qingjin Meng
https://avianmusing.blogspot.com/

If that is the case, should we still be calling these ancient traits “processes”? Or is their presence in the fossil record more in line with sesamoid bones?

In anatomy, a sesamoid bone is a bone embedded within a tendon or a muscle. Although they are a special structure that is technically independent of the main skeleton, sesamoids begin their development much like regular bony tissue. Specialized bone-generating cells gather at the appropriate point and are nurtured by a locally enhanced blood supply. After initial mineralization, there is a period of remodeling so that the new bone can meet any special role it might play in the movement of neighboring bones (Source: Kaiser, G. 2007. The Inner Bird, Anatomy and Evolution).

The fossil of Citipati osmolskae, from the Late Cretaceous of Mongolia, has a single isolated uncinate process visible in top righthand corner of the specimen indicating how easily these small bones could be lost in otherwise complete specimens (see source below).

Citipati osmolskae with isolated uncinate process 
Image Credit: Codd J.R. 2004
https://avianmusing.blogspot.com/
http://hss.ulb.uni-bonn.de/2004/0424/0424.pdf

Even stranger than the fossils unossified processes is that of the Southern Screamer (Chauna torquata), the only bird which lack the uncinate process entirely. 


Southern Screamer (Chauna torquata) ribs lacking the uncinate process
Photo Credit: Paul Cianfaglione
https://avianmusing.blogspot.com/

Wednesday, February 6, 2019

The Hummingbird as Warrior: Evolution of a Fierce and Furious Beak

The Hummingbird as Warrior: Evolution of a Fierce and Furious Beak

By James Gorman

Feb. 5, 2019

If you want to know what makes hummingbirds tick, it’s best to avoid most poetry about them.

Bird-beam of the summer day,

— Whither on your sunny way?

Whither? Probably off to have a bloodcurdling fight, that’s whither.

John Vance Cheney wrote that verse, but let’s not point fingers. He has plenty of poetic company, all seduced by the color, beauty and teeny tininess of the hummingbird but failed to notice the ferocity burning in its rapidly beating heart.

The Aztecs weren’t fooled. Their god of war, Huitzilopochtli, was a hummingbird. The Aztecs loved war, and they loved the beauty of the birds as well. It seems they didn’t find any contradiction in the marriage of beauty and bloodthirsty aggression.

Scientists understood that aggression was a deep and pervasive part of hummingbird life. But they, too, have had their blind spots. The seemingly perfect match of nectar-bearing flowers to slender nectar-sipping beaks clearly showed that hummingbirds were shaped by co-evolution.

Image Property of: Kristiina Hurme, NY Times
https://avianmusing.blogspot.com/
Continue reading this very interesting article here, be sure to also watch the video;

Tuesday, February 5, 2019

First discovered fossil feather did not belong to iconic bird Archaeopteryx Imaging technology shows first discovered fossil feather did not belong to iconic bird Archaeopteryx

First discovered fossil feather did not belong to iconic bird Archaeopteryx

Imaging technology shows first discovered fossil feather did not belong to iconic bird Archaeopteryx

Originally published by;

Science Daily; your source for the latest research news


Date:

February 4, 2019

Source:

The University of Hong Kong

Summary:

A 150-year-old fossil feather mystery has been solved. Researchers applied a novel imaging technique, laser-stimulated fluorescence, revealing the missing quill of the first fossil feather ever discovered, dethroning an icon in the process.

Image Property of University of Hong Kong
https://avianmusing.blogspot.com/
A 150-year-old fossil feather mystery has been solved by an international research team including Dr Michael Pittman from the Department of Earth Sciences, The University of Hong Kong. Dr Pittman and his colleagues applied a novel imaging technique, Laser-Stimulated Fluorescence (LSF), revealing the missing quill of the first fossil feather ever discovered, dethroning an icon in the process.

This fossil feather was found in the Solnhofen area of southern Germany in 1861. The isolated feather was used to name the iconic fossil bird Archaeopteryx and was closely identified with its skeletons. Unlike the feather impressions preserved in some Archaeopteryx fossils, the isolated feather is preserved as a dark film. The detailed 1862 description of the feather mentions a rather long quill visible on the fossil, but this is unseen today. Even recent x-ray fluorescence and UV imaging studies did not end the debate of the "missing quill." The original existence of this quill has therefore been debated and it was unclear if the single feather represented a primary, secondary, or primary covert feather.

The results of this study are described in the journal Scientific Reports, and underscore the potential and scientific importance of Laser-Stimulated Fluorescence, which is being developed by Thomas G Kaye of the Foundation for Scientific Advancement, USA and Dr Pittman. "My imaging work with Tom Kaye demonstrates that important discoveries remain to be made even in the most iconic and well-studied fossils," says Dr Pittman.

With the help of the LSF images, the team finally solved the 150-year-old missing quill mystery. The now completely visible feather allowed detailed comparisons with the feather impressions of Archaeopteryx and with living birds. Before this LSF work, the feather was thought to represent a primary covert from Archaeopteryx, but this study shows that it differs from coverts of modern birds by lacking a distinct s-shaped centerline. The team also ruled out that the feather represented a primary, secondary, or tail feather of Archaeopteryx. Instead, the new data indicates that the isolated feather came from an unknown feathered dinosaur and that its attribution to Archaeopteryx was wrong. "It is amazing that this new technique allows us to resolve the 150-year-old mystery of the missing quill," says Daniela Schwarz, co-author in the study and curator for the fossil reptiles and bird collection of the Museum für Naturkunde, Berlin. This discovery also demonstrates that the diversity of feathered dinosaurs was likely higher around the ancient Solnhofen Archipelago than previously thought. "The success of the LSF technique here is sure to lead to more discoveries and applications in other fields. But you'll have to wait and see what we find next!'' added Tom Kaye, the study's lead author.

Saturday, February 2, 2019

Evidence for Bipedal Prosauropods as the Likely Eubrontes Track-Makers? A Pictorial Reaction.

Just days after giving a lecture to a local Connecticut birding club on the Reverend Edward Hitchcock (Jurassic Bird Tracks), came the shocking news that a researcher had recently published evidence for bipedal Prosauropods as the likely Eubrontes track-makers in the Central Valley of Connecticut and Massachusetts (Robert E. Weems. Published online: 19 Jan 2019).

Though I haven’t read the research paper myself (Journal Ichnos. An International Journal for Plant and Animal Traces), I did read the abstract, as well as listened to a commentary about the article on a Dinosaur Podcast. 


From what the abstract has implied, it seems that everything that I have ever read, or known about the track makers in my Connecticut backyard, was now all for nothing. Even worse, did my recent talk provide ill-timed misinformation? 

Eubrontes giganteus tracks
Dinosaur State Park, Rocky Hill, Connecticut
https://avianmusing.blogspot.com/
The abstract lays out the researcher’s claims here;

   *The tridactyl ichnotaxon Eubrontes giganteus commonly has been attributed to a carnivorous theropod dinosaur similar to Dilophosaurus or Liliensternus. For this to be correct, however, at least five unusual circumstances all must be true. (1) If the Eubrontes track-maker was a theropod, it created the most abundant large tracks found in the Connecticut Valley Hartford and Deerfield basins and yet, for unknown reasons, left no skeletal remains there at all. This pattern also holds true for the Kayenta Formation and Navajo Sandstone in the American Southwest. (2) The cursorial, bipedal, functionally tridactyl prosauropod Anchisaurus, which left two-thirds of the skeletal remains found in these same basins, for unknown reasons left no tracks there at all. (3) If the Eubrontes track-maker was a theropod, by happenstance, it was a theropod exactly the same size as Anchisaurus. (4) If the Eubrontes track-maker was a theropod, then published evidence for herding by Eubrontes track-makers must be due to local paleogeographic factors, not recognizable in the rock record, which created an illusion of herding. (5) The known stratigraphic range of Eubrontes tracks (Norian-Toarcian) by happenstance falls entirely within the known stratigraphic range of bipedal prosauropods (upper Carnian-Toarcian). None of these unusual circumstances need be true, however, if Anchisaurus was the Eubrontes track-maker. Recent reports of an anteriorly directed hallux in the Eubrontes track-maker provide compelling evidence that prosauropods, not theropods, made Eubrontes tracks. Parsimony strongly favors this conclusion and weighs heavily against the idea that the Eubrontes track-maker was a mysterious, elusive theropod whose skeletal remains have evaded discovery for nearly two centuries*.

I would like to go over some of the authors points (unusual circumstances), by providing alternative information from the book; Windows into the Jurassic World, by Nicholas G. McDonald (2010). 

Window into the Jurassic World by Nicholas G. McDonald
https://avianmusing.blogspot.com/

Unusual circumstance number one.

(Author) If the Eubrontes track-maker was a theropod, it created the most abundant large tracks found in the Connecticut Valley Hartford and Deerfield basins and yet, for unknown reasons, left no skeletal remains there at all.

Yes, it is true, there are no skeletal remains of theropods here in the Northeast United States. However, there are also very few, if any, dedicated excavation sites in the Hartford Basin for discovering dinosaur remains. All of the handful of complete Anchisaurus skeletons have come from old quarries when they were in operation. If the Northeast landscape was truly “user friendly” to paleontologists over the last two-hundred years, Yale, or any other large institution would have made a concerted effort to explore and dig here. Instead, they chose the American West and other countries because dinosaur bones, quite frankly, were more abundant and easier to find there. To make matters worse, one of the most promising places to find a theropod skeleton in Connecticut today (Manchester) currently has an enormous shopping mall on top of it. Every other location that isn’t developed, is completely forested.

Despite the lack of theropod skeletal remains, there is evidence of large theropod existence in Connecticut when a 0.75-inch tooth was found in 1970 during excavations in North Guilford, CT. 
   
Connecticut Theropod Tooth
Image From: Window into the Jurassic World by Nicholas G. McDonald
https://avianmusing.blogspot.com/

Unusual circumstance number two.

(Author) The cursorial, bipedal, functionally tridactyl prosauropod Anchisaurus, which left two-thirds of the skeletal remains found in these same basins, for unknown reasons left no tracks there at all.

According to Nicholas McDonald in Windows into the Jurassic World;

   *Unlike the four-toed theropods, the hind foot (pes) of Anchisaurus had five digits. Four of the toes were large, with numerous small pads and blunt claws. The narrow hand (manus) of this animal also had five digits, with the fourth and fifth digits being smaller and clawless. The thumb was equipped with a large curved claw, which might have been used to pull down tall vegetation, to dig up edible roots, or as a defensive weapon. Unfortunately, the hand and foot structure of Anchisaurus cannot be matched up with any known tracks from the Central Valley, but the very large tracks called Otozoum are thought to have been made by a much larger prosauropod relative*. 

Foot Bones of Anchisaurus
Image From: Window into the Jurassic World by Nicholas G. McDonald
https://avianmusing.blogspot.com/

Unusual circumstance number three.

(Author) If the Eubrontes track-maker was a theropod, by happenstance, it was a theropod exactly the same size as Anchisaurus.

     *The size of a Eubrontes footprint and its estimated overall size according to Wikipedia is; typical Eubrontes print is from 25–50 cm long, with three toes that terminate in sharp claws. It belongs to a biped that must have been over one meter high at the hip and from 5–6 meters long. Anchisaurus was a rather small dinosaur, with a length of just over 2 meters (6.6 ft). Gregory S. Paul estimated its length at 2.2 meters and its weight at 20 kg in 2010.

Unusual fact number one.

(Author) Recent reports of an anteriorly directed hallux in the Eubrontes track-maker provide compelling evidence that prosauropods, not theropods, made Eubrontes tracks.

     *Personally, as an on and off again theropod track collector, I have never seen a Eubrontes track with anything that ever suggested anteriorly directed hallux. Seems to be either a misidentification (Otozoum or sitting Anomoepus?), or two theropod prints, one on top of the other. 

Otozoum and Grallator tracks from Portland, Connecticut
Image From: Window into the Jurassic World by Nicholas G. McDonald
https://avianmusing.blogspot.com/



 

Friday, February 1, 2019

Avian Grief and Emotions. Are they real?

Bird observation is seldom a lengthy event, mostly occurring for only a brief moment in time. My latest observation was therefore predictably short, but even so, clearly touched a raw nerve.  

Despite its brevity, the sight of two cawing American Crows (Corvus brachyrhynchos) perched low along the edge of a busy highway, gazing down upon a fallen companion, was very telling.   

What really was going on here?

Did the crows close proximity to the corpse signal a possible feeding opportunity? Or was the sight of dead kin just a mere passing curiosity? I believe both of these suggestions are incorrect.

To me, this was a clear case of birds feeling grief, actual emotions.

In recent years, the scientific community has become increasingly supportive of the idea of emotions in animals. However, most of the research has shown a lack of clear-cut evidence, or have had questionable results.

It is often mentioned that humans have emotions and that it is something fundamental and important in our lives, however it is hard to say if that is true for animals or just some.

Critics also point to the fact that animals having no linguistic means to communicate emotion beyond behavioral response interpretation, the difficulty of providing an account of emotion in animals relies heavily on interpretive experimentation, that relies on results from human subjects*. (Source: Wikipedia; Emotion in animals)

Yet, it is pretty clear from countless examples (see link below), that animals such as elephants, dolphins, wolves and primates, do show various outward emotions.


How do we begin to make sense of all of this? Do we take the indecisive position and hope for better scientific data to come along? Or do we let the animal actions speak for themselves?

What will it ultimately take to convince people that a living, breathing animal, other than ourselves, feels pain, gratitude, sadness and joy?

What are the mental barriers that prevents us from accepting the obvious? Is it, religious policy, egotism, narrow-mindedness?

Below is another example that helped convince me that birds have certain emotions;

   *One morning while driving in to work, I noticed what appeared to be a dead Blue Jay (Cyanocitta cristata) lying in the middle of the road. I stopped my car to collect the remains, but soon realized that it was still alive with a broken back. I leaned down to assess the situation, and while doing so, two other jays landed right beside me, quietly watching my every move. It was a surreal moment*.

Wild Blue Jays, I can assure you, never come this close to humans, but in this case, expressed grave concern for their injured friend, even at the expense of their own safety.  

Scientist Marc Bekoff provides further evidence of birds being able to experience emotions in his book, The Emotional Lives of Animals. The following is an excerpt from that book (source Wikipedia):

[A few years ago, my friend Rod and I were riding our bicycles around Boulder, Colorado, when we witnessed a very interesting encounter among five magpies. Magpies are corvids, a very intelligent family of birds. One magpie had obviously been hit by a car and was lying dead on the side of the road. The four other magpies were standing around him. One approached the corpse, gently pecked at it-just as an elephant noses the carcass of another elephant- and stepped back. Another magpie did the same thing. Next, one of the magpies flew off, brought back some grass, and laid it by the corpse. Another magpie did the same. Then, all four magpies stood vigil for a few seconds and one by one flew off.]

Black-billed Magpies (Pica hudsonia) Grief.
Image Property of: Mark Bekoff
https://avianmusing.blogspot.com/
As researchers continue to make great advances in the study and acceptance of animal emotions science, I believe it is equally important that we continue to share with others personal life experiences, as well as inspiring visual examples found on social media. 


Emperor Penguin Mourns
Photo Credit: BBC Earth
https://avianmusing.blogspot.com/


In my opinion, I find the denial of emotions and grief in animals, other than ourselves, to be out-and-out self-centeredness.

Ironic of all is the idea that we do not accept emotions in animals here on earth, but insist that communication and reasoning will be had with alien life forms from other planets!