Readers’ wildlife photos

April 6, 2021 • 8:30 am

by Greg Mayer

For today’s post we return to the New York City Subway 8th Avenue local (B and C trains) station at 81st-Museum of Natural History,this time for the amphibians.

81st St.-Museum of Natural History station, New York subway, July 17, 2019.

My favorite of the amphibians is this brooding caecilian, curled round its eggs. These legless, short-tailed amphibians are found only in the tropics, and there is no real English vernacular name for them. (You can find a Sicilian in the subway, but I prefer Neapolitan.)

Brooding caecilian. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

What appears to me to be a reed frog (Hyperolius sp.), an African tree frog of sorts, hangs on the wall next to a station identifying sign.

Reed frog. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

This looks like a ranid frog to me– a member of the family Ranidae, perhaps intended to be a Rana proper. Many species in this and related genera look much alike the world over. Note the nicely delineated tympanic membrane.

Frog. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

This generic frog (I won’t even try to name a family for it) is leaping out of the Signal Room. Interestingly, the subway workers here believe in free will, apparently of the libertarian sort. A scratched note on the door reads, “Use other door→ | or this one– up to you”.

Frog. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

These well-rendered salamanders provide detail enabling specific identification. On the left we have a Marbled Salamander (Ambystoma opacum), a species of eastern North America (including the New York area), and on the right we have a Fire Salamander (Salamandra salamandra), a species widely distributed in Europe. The American Tiger Salamander (Ambystoma tigrinum; found in the New York area) is also black with yellow markings, but the yellow markings (quite variable in both species) look more like Salamandra to me, and the evident parotoid glands at the back of the head (making it look wide) are conclusive. Ambystoma and Salamandra are similar in size and body shape, and are sort of continental ecological analogues.

Salamanders. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

The Coelacanth (Latimeria chalumnae) is one of the few surviving lobe-finned fishes, and as such is one of the tetrapods closest living relatives, and so is included here as an honorary amphibian. I don’t know why there is a question mark on its tail; in fact I never noticed it there before till just now.

Coelacanth. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Finally, we have a group of patently Paleozoic fish. The artist has rendered them neither strictly from above (as though we were looking down on them in the ‘water’ of the paving tile) nor from the side, but in a sort of twisted view, allowing us to see various aspects. The bottom four may be intended to be the same type of fish (I’m not sure what kind), but the top one (which seems to be more of an exclusively side view– see the partly opened mouth) looks like one of those strange Paleozoic sharks, with a spiny first dorsal fin, and a heterocercal tail. You can also see more clearly in this photo how the lighter brown granite-like stone is integrated with the darker paving tile.

Fish on the floor. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

There are other taxa represented in the tiles (e.g., ants), and other forms of art, including larger tiled murals, and casts of in-situ fossils projecting from the wall. Many of these works are depicted in a gallery at www.nycsubway.org, a subway fan/history site. Some of those depicted I’ve never seen in person, because I always exit the station at the south (Museum) end, not at the north (81st Street) end.

(Looking at one of the pictures in the gallery now, I see the undersea mosaic mural has  a coelacanth-shaped gray silhouette in the otherwise colorful tiles; could the question mark noted above be related to the coealcanth’s absence here?)

Readers’ wildlife photos

April 5, 2021 • 8:30 am

by Greg Mayer

Today’s post features subterranean wildlife, but not of the fossorial kind. It has wildlife you can see in the New York subway, but it’s not “pizza rat” or his later avatars: it’s the wildlife art of the 8th Avenue local (B and C trains) station at 81st-Museum of Natural History.

81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Elegant tile-work has long been a signature note of the New York subways, and when the station was renovated (reopening in 2000), the American Museum of Natural History and the Metropolitan Transportation Authority collaborated in creating extensive artwork for the station, one of whose exits goes directly into the Museum.

We’ll start with my favorite, what is clearly a hatchling Green Anole (Anolis carolinensis; the proportions, especially the large head, show it’s a hatchling). The Museum clearly had significant input on the designs, although it’s not always clear if the artists followed exact specifications for species identification, but in this case I’m confident. Important work on anoles was done by former curators James Oliver and G.K. Noble, and the latter’s anole work was mostly on this species.

Hatchling green anole (Anolis carolinensis). 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

We’ll continue with the rest of the lizards. The next is clearly a monitor lizard, and it’s bulk indicates it’s a Komodo Dragon (Varanus komodoensis).

Monitor lizard. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Next up is a basilisk or Jesus Christ lizard (Basiliscus sp.), famed for their bipedal locomotion, which includes the ability to skitter Christ-like across the surface of bodies of water for short distances. This mosaic introduces an element common to the artwork, the depiction of extinct forms as grayed “ghost” silhouettes, often paired with an extant form. In this case we have two bipedal diapsids: the basilisk and the theropod dinosaur Deinonychus (note the ‘terrible claw’ and short snout); the latter is about life size, but the basilisk is greater than life size. (This is an estimate, but I think the white tiles are either 4″X4″ or 5″X5″; if anyone knows the size–or can measure!–put it in the comments.)

Basilisk with ghost Deinonychus. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

There’s a chameleon (Chamaeleo sp.). I’ve not attempted to determine the species. (It could be intended to be a species in another genus in the family Chamaeleontidae, but Chamaeleo is the type genus, and will do as at least approximately correct.) A nice detail is that the zygodactlous left front foot (‘hand’) can be seen grasping the black tiles, as though the latter constituted a tree branch. (The hind feet are curiously stubby-looking.)

Chameleon. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Snakes are, of course, just glorified lizards. This one’s head and neck, and the fact that it hangs from the ‘branch’ make it look like a vine snake, but I’ll offer no more of a guess than that. Note how, as in the Chamaeleo above, the artwork can ‘overlay’ the regular wall design.

Snake. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Next is a fairly nondescript snake, superimposed on the long tail of a long-necked sauropod dinosaur. The whole dinosaur looked like Diplodocus to me.

Snake with ghost sauropod dinosaur. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Having finished the order Squamata, we move on to the Tuatara (Sphenodon punctatus), not a lizard, but the sole living member of the order Rhynchocephalia. This is another of my favorites.

Tuatara. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

This broad-snouted crocodilian looks like an alligatorid, and is nicely paired with a Stegosaurus. Were it black, I would readily identify it as an American Alligator (Alligator mississippiensis), but the greenish-brown color makes me hesitate. The details of form in this one are not as satisfying as they are in most of the others. Note how the tail tip, which extends on to the dark paving tiles of the floor and trim, is rendered in a different type of tile.

Alligatorid with ghost Stegosaurus. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Next is another favorite, an adult male Gharial (Gavialis gangeticus). The two things I like most about this one are the inclusion of the narial excrescence, a rarely depicted seasonally-present secondary sexual character of male gharials, and that the dark paving tile stones are treated as the ‘water’, from which the Gharial emerges. The dark stone is replaced with a lighter brown granite-like material to indicate the parts ‘underwater’. If you enlarge the image and look carefully, you can see that the outline of the Gharial is also continued into the glossy black enamel tiles. Although not visible in this photo, the body curls through the enamel tiles, and the Gharial’s tail re-enters the paving tiles, to again be represented by the granite-like stone.

Male Gharial (Gavialis gangeticus). 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

Finishing up the reptiles we have a giant tortoise. The surviving species of giant tortoise are from Aldabra Atoll in the Indian Ocean and the Galapagos Islands in the Pacific. The somewhat high front opening of the carapace is more characteristic of some of the subspecies of the Galapagos Tortoise (Geochelone elephantopus) than of the Aldabra Tortoise, and so I will go with that as a species identification.

Giant tortoise. 81st St.-Museum of Natural History station, New York subway, July 17, 2019.

We’ll finish off our subway tour with the amphibians and a few fish tomorrow.

Teddy Roosevelt and the American Museum of Natural History

June 29, 2020 • 9:00 am

JAC: People keep thinking that I’m the author of everything on this site. While that’s usually true, we also have occasional contributions from others, most often from Greg Mayer, a biology professor at the University of Wisconsin-Parkside. And this comes from him.

by Greg Mayer

Readers of WEIT may recall that last Monday Jerry noted that, according to the NY Times, President Ellen Futter of the American Museum of Natural History has decided that the statue of Theodore Roosevelt that stands in front of the Museum’s entrance on Central Park West will be removed. I’ve (almost) given up on the University of Wisconsin, but some institutions are still worth fighting for. It took me a few days to compose a letter, and below is what I sent her on Friday.

Theodore Roosevelt equestrian statue, Theodore Roosevelt Memorial, American Museum of natural History, 14 June 2019.
Ms. Ellen Futter, President
American Museum of Natural History
Central Park West at 79th Street
New York, NY 10024
Dear President Futter:
I am writing to you to express my dismay at your decision to remove the statue of Theodore Roosevelt from in front of the the Rotunda entrance of the Museum.
I hope I need not have to recount for you Roosevelt’s close association with the Museum during his lifetime, and his many contributions to natural history as a naturalist, collector, conservationist, and scientist. The State of New York chose the Museum as the location for its memorial to Roosevelt in all his fields of endeavor– politician, public servant, soldier, statesman, author– not just in natural history.
As a conservationist, his historical importance is unparalleled, because, as Governor and President, he was able to act on his principles. He expressed these principles succinctly in a letter to Frank Chapman, one of the Museum’s curators, while he was Governor:
The destruction of the wild pigeon and the Carolina paraquet has meant a loss as severe as if the Catskills or Palisades were taken away. When I hear of the destruction of a species I feel just as if all the works of some great writer had perished[.]
As a scientist, Roosevelt is one the very few presidents who, as a much published student of the natural world, can be counted among the company of scientists. During a recent visit to the Museum to do research, I had the pleasure of examining in the Bird Library a copy of Roosevelt’s paper on animal coloration, published in the Museum’s Bulletin in 1911, one of the only scientific papers published by a president.
The statue itself presents Roosevelt in Western frontier garb, while at his side are a figure of an American Indian and an African. The American West and Africa were extremely important in Roosevelt’s development and career as a naturalist, and he wrote much of his experiences in both places. The figures represent not conquered peoples, but the people and places with whom, and where, Roosevelt lived and worked during his years in the West and during his year-long African expedition. The entrance outside of which the statue stands leads, appropriately, into the Akeley Hall of African Mammals– a hall which had been planned to be called the “Roosevelt African Hall”.

Your effort to cast the removal of the statue not as a repudiation of Roosevelt, but as a critique of the statue’s “composition”, is a transparent stratagem, and is even more disreputable, making the statue’s removal an aesthetic whim, rather than an ideological act. Realistic depiction of allegorical figures in a pyramidal shape may not be the fashion today, but it is the essence of a museum to conserve, display, and interpret natural and cultural artifacts from all of time and history, not to get rid of those that go out of style.

Those calling for the statue’s removal may be well-intentioned (though ill-informed– those who defaced the statue a few years ago thought the figure to Roosevelt’s left was an African-American). But good intentions and justified grievances are not enough to excuse the act of iconoclasm  that you are contemplating. The English Reformation may have had some good points in its critique of the Catholic Church, but that did not justify the destruction of the monasteries and the loss of their libraries– a severe loss, just as Roosevelt himself wrote to Chapman.
To remove the statue is to condescend to the misdirected passions of the crowd, no matter how just the essence of their grievances. I urge you resolutely to reconsider your decision.
With all best wishes,
Gregory C. Mayer
Professor of Biological Sciences
University of Wisconsin-Parkside

A couple of notes on items in the letter; some of these points are not explicated in the letter, because I assume Futter would know them. First, the entrance to the Museum here leads into the Theodore Roosevelt Rotunda, which is a large space containing an Allosaurus attacking a Barosaurus, as well as various memorials to Roosevelt. The floor below the Rotunda houses the Theodore Roosevelt Memorial Hall, also with memorials to Roosevelt, including a bronze sculpture of Roosevelt sitting on a bench (alongside which many pictures have been taken). This whole section of the Museum, together with the plaza, facade, and statues, constitute The New York State Theodore Roosevelt Memorial. Second, Roosevelt’s letter to Frank M. Chapman may be found here. Third, the earlier misinformed protests alluded to are the subject of this NY Times article. And finally, if you want to know more about Roosevelt as a naturalist and his connection to the Museum, Darrin Lunde’s The Naturalist: Theodore Roosevelt, A Lifetime of Exploration, and the Triumph of American Natural History  (Crown Publishing, 2016) is a good place to start.

Theodore Roosevelt equestrian statue, Theodore Roosevelt Memorial, American Museum of natural History, 14 June 2019.

I grew up on Long Island, both sides of my family are from Brooklyn, and my father worked in the City. As a budding naturalist, though my attention focused on the Bronx Zoo, the American Museum did not escape my notice as a source of wonder, amazement, and knowledge. Until I went to grad school at the Museum of Comparative Zoology, the American Museum was “my” museum. I visited, and continue to visit, the American Museum to examine specimens for my research. In fact, for the last few years, I’ve been visiting the American Museum almost every year (because of the extraordinary richness of their collections for a project I’ve been working on).

Theodore Roosevelt equestrian statue, Theodore Roosevelt Memorial, American Museum of natural History, 14 June 2019.

The first thing I did as I contemplated my response was to check what info I immediately had to hand about the Museum and Roosevelt. I was surprised to find I had more than a dozen books about the Museum, its collections, and its history. The earliest I purchased in 1975, during a high school field trip; the latest I bought during a research visit last year. I doubt I’ll get a reply; the only time I’ve gotten a reply to such a letter to a higher up was a letter to Harvard, and they knew I was an alum. My hope is that if enough criticism is voiced, there might be a reconsideration.

Theodore Roosevelt equestrian statue, Theodore Roosevelt Memorial, American Museum of natural History, 14 June 2019.

The defenestration of statues is reaching absurdist territory, with two recent take downs in Madison. Protesters pulled down the statue “Forward” outside the State Capitol. The statue is described by the Wisconsin Historical Society like this:

“Forward” is an allegory of devotion and progress, qualities [sculptress Jean Pond] Miner felt Wisconsin embodied.

The statue has often featured, as a positive symbol, embraced by protesters, in demonstrations in protests for women’s rights, gay rights, labor,  etc. The current protesters are either abysmally ignorant, or actually oppose progress.

Forward in better days. Amber Arnold, Wisconsin State Journal Archives.

 

Forward, as recently defaced. She was subsequently pulled down and thrown in the street. Amber Arnold, Wisconsin State Journal.

Even more bizarre is the destruction of the statue of Hans Christian Heg, an abolitionist and Union officer who was killed by Confederates while leading his troops at the Battle of Chickamauga. Heg was originally from Norway, and the Norwegian media have taken note of the statue’s destruction. This excerpt, from a Norwegian piece entitled “Historians Puzzled After Statue Razed” sums it up:

Norwegian officials were surprised and saddened by news that the statue of a Norwegian-American anti-slavery activist is among the latest to be toppled and dumped in a river by demonstrators in the US state of Wisconsin. Hans Christian Heg opposed slavery and fought for the Union Army during the Civil War. . . .

Colonel Hans Christian Heg became a symbol of Norwegians’ anti-slavery activism. He was shot and killed during the Civil War while leading a Union regiment against the South’s Confederates, so Norwegians can’t understand why his statue became a target of anti-racism demonstrators.

It’s not just Norwegians that can’t understand. As a local reporter put it, the statues’ destruction left “many people wondering what purpose their removal served to advance the Black Lives Matter movement.

The tearing down of statues has now become indiscriminate. In Madison (again), students at the university are now calling for the removal of a statue of Lincoln. (Everybody hates Lincoln, apparently.) In San Francisco, a statue of Ulysses Grant was actually taken down! Do the demonstrators know nothing at all about American history?

That the latter is actually the case is suggested by a remark made to NBC News by a demonstrator at an attack on a statue of Andrew Jackson, to the effect he was getting rid of “Confederates”. This is absurd. Jackson was a staunch Unionist. During the nullification crisis of the 1830s, Jackson firmly opposed nullification and secession, and, at his behest, Congress passed a bill authorizing him to take military action against South Carolina. According to Britannica,

Jackson’s actions in asking for the Force Bill were seen by nationalists as a heroic move that preserved the integrity of the Union and underscored the primacy of the federal government.

Jackson was a Southerner and slave-owner, but we don’t know what he would have done thirty years later, because he was long dead by the time of the Civil War. (You should read, by the way, Jackson’s proclamation on nullification, simply as an example of argumentation. I’m not sure if he wrote it himself, but it’s a rhetorical tour de force compared to what emanates from the current president.)

One of my greatest concerns is that these events are providing the perfect ammunition for Trump’s re-election campaign. You may think that tearing down Lincoln, Grant, and Civil War heroes is the action of a few zealots, and I hope that’s true. But four years ago I thought the follies of the academic authoritarian left were an academic sideshow, but it turned out Fox News was broadcasting these follies 24/7. The events in Madison have not gotten much coverage from other national media, but Fox is already making hay of these events; (video here; more coverage).

In seeing what is going on, I thought, “This is like the Cultural Revolution”; Andrew Sullivan had similar thoughts. If Lincoln, Grant, and Heg cannot pass muster, then no one can.

Central Park squirrel census

January 11, 2020 • 7:45 am

Because of a paucity of readers’ wildlife photos (I do have some, so if you sent them have patience), I’m deferring posting those till tomorrow, replacing them with a SQUIRREL CENSUS post by Greg:

by Greg Mayer

We’ve long been fans of squirrels here at WEIT, and so I was quite pleased to come across the following item in the New York Times, a combination of text, audio, video, and stills, on a census of the gray squirrels (Sciurus carolinensis) in Central Park. (Be sure to have the sound on for the squirrel vocalizations.)

https://www.nytimes.com/interactive/2020/01/08/nyregion/central-park-squirrel-census.html?

And it’s not just because it’s squirrels– it’s the location, too. Research takes me every year or two to the American Museum of Natural History, which is located on Central Park West between 77th and 81st Streets, and I often walk across to Central Park to have lunch, where I enjoy the wildlife, including the squirrels. Mike Klemens of the American Museum did a herpetological inventory of Central Park, which I’ve remarked upon here at WEIT (the only herps I’ve ever seen are turtles in Turtle Pond), so I’m glad to see the squirrels get their due.

The Times also had two earlier articles about the start of the census, here

and here:

Going through the multimedia piece on the results of the inventory, I noticed this photo. . .

Screenshot_2020-01-09 There are 2,373 squirrels in Central Park I know because I helped count them .png

. . . of a melanistic squirrel in the Park. This is interesting for two reasons. First, I didn’t know there were black squirrels in Central Park—I’ve never seen one. (In New York City, “black squirrels” are a color form of the gray squirrel; in other places, the “black squirrels” may be fox squirrels, Sciurus niger.) Second, it shows that the black squirrels are not all blacks (sorry, New Zealand!), but usually have some reddish color in them. In the one above, the belly is quite extensively reddish; in black squirrels I’ve gotten close enough to see, there’s usually some red color on the back, although their appearance depends on the lighting; and from a distance they may appear all black.

I was hoping to look at the report of the squirrel census to see the prevalence and distribution of the black squirrels (as well as to find other fun squirrel facts), but was disappointed to find that the report will cost you $75! But, a single ring chart was visible on the census website—in a copy of the report opened to show what you would be paying for—and this chart shows that there were 140 black squirrels out of 3938 squirrels whose color was recorded: a frequency of 3.56%. (There’s also mention of a more common “cinnamon” morph, but I’m not convinced that’s a distinct morph.)

The Times piece also provided some bits of data. From the following figure, I was able to determine that of 2969 squirrels with a known color depicted, 103 were black, for 3.47%. (The “white” squirrels in the figure, 54 of them, are actually blanks—squirrels with no color data recorded. The pie chart had 74 such missing-data squirrels.)

Screenshot_2020-01-09 2 There are 2,373 squirrels in Central Park I know because I helped count them .jpg

I’m not sure why there are 3023 squirrels total in the Times‘ figure, but 4012 in the ring chart, but the two estimates of the prevalence of the black phase, 3.56 and 3.47%, are very close. It’s no wonder then, that the handful of squirrels I would see during my Central park rambles would not include any black ones.

In a nice “squirrel map” of all the sightings in Central Park in the Times piece, there are about 3 or 4 black squirrels recorded in the part of the park between the American Museum and the Turtle Pond, so they do occur there, but, again, at low frequency, so no surprise I haven’t seen them.

(Here are some earlier WEIT posts on color polymorphism in squirrels.)

Pterosaurs take Manhattan

April 11, 2014 • 9:42 am

by Greg Mayer

Last weekend, a new exhibit opened at the American Museum of Natural History in New York: “Pterosaurs: Flight in the Age of Dinosaurs“. The New York Times had a piece on the making of the exhibit last week, and today their museum critic, Edward Rothstein, weighs in with his take on the pterosaurs. We’ve had occasion to favorably note Rothstien’s reviews previously here at WEIT, and his conclusion is that the exhibit is well worth seeing.

pterosaurs-lead_homepage_slide

He writes:

The exhibition is unusually compelling, given its directness and simplicity. In one sense, pterosaurs are quite familiar: Any image of the dinosaur age shows them ruling the skies. But as you work your way through this exhibition, they become confoundingly strange. Walking on wings! A fourth finger for flying! Crests larger than heads!

His review also considers how it is we come to know about the pterosaurs (‘pterosaur epistemology’), the serendipity of fossilization and discovery, and how small clues can be used to build up a more complete picture of the creature, noting, for example  how a small mass of ejected bones (a gastric pellet), which might be overlooked, reveals what pterosaurs ate.

It reminds us of what exists before hypotheses accumulate, and what the paleontologist must accomplish, combining meticulous examination with speculative reconstruction. The pellet presents just a slightly more extreme version of how many pterosaur fossils are found. Some are seen here: jumbles of flattened bones and random filaments, gastric pellets spat out of some geological maw. …

Out of accidents, order takes shape; we see this to be as true of the paleontologist’s enterprise as it is of evolutionary change. The effect is to make us wonder which is more marvelous: the creatures themselves, or the ways they have been recreated?

The accompanying website is chock full of images, videos and information– go have a look. Here’s a nice summary video.

Some aspects of the reconstructions are speculative– we don’t really know what colors their crests were (although we do have evidence for the color of some Mesozoic reptiles). And, surprisingly to me, there is almost nothing about the “hairs”– called “pycnofibers”–  that have been described in a number of pterosaurs. I’ve always thought the suggestion of pterosaurs being haired was very exciting, and, if true, a nice example of convergence, and evidence that pterosaurs were warm-blooded. The only mention I can find on the AMNH site concerns Jeholopterus, a small pterosaur with pycnofibers,  seen in the following gif:

Jeholopterus, a "haired" pterosaur (AMNH).
Jeholopterus, a “haired” pterosaur (AMNH).

Pterosaurs are, of course, reptiles (and not dinosaurs!), and one of the three groups of tetrapods to have evolved true flight (as opposed to gliding, which has evolved many more times). Pterosaurs’ air foil is membranous skin, stretched along an enormously elongated 4th finger; bats, too, have a membranous wing, but it is supported by fingers 2 through 5; birds have a wing of feathers, which project not from elongated finger bones, but from a shortened and fused set of hand/finger bones. These structures are nicely illustrated in the following figure from Steve Gatesy and Kevin Middleton:

Pterosaur (A), bird (B), and bat (C) wings. Gatesy & Middleton, 2007.
Pterosaur (A), bird (B), and bat (C) wings. Gatesy & Middleton, 2007.

Powered flight is thus an excellent example of convergent evolution— the origin of similar structures as adaptations to similar conditions of existence. The wings, because they evolved independently, are said to be analogous (i.e. not derived from a common ancestor possessing wings), as is evident from the different nature of the air foil, and the different modifications of the bones involved in the wings of the three groups– the similarities are superficila nad functional. It also nicely shows the hierarchical nature of homology. The front limbs of bats, birds, and pterosaurs are homologous as limbs (i.e. derived from a common ancestor possessing front limbs), but not as wings. The common structures (humerus, radius, ulna, etc.) are homologous at the level of tetrapods, but the modifications of these structures as wings are separate evolutionary events.

The exhibit is temporary, and will be up through January 4, 2015. Be sure to put it on your list of things to see while in New York; it’s on mine!

________________________________________________________________

Gatesy, S.M. and K.M. Middleton. 2007 Skeletal adaptations for flight. pp. 269-283 in Hall, B.K., ed., Fins into Limbs: Evolution, Development, and Transformation. University of Chicago Press, Chicago.