Friday, June 3, 2016

Dinosaurs Among Us at the AMNH

Upon learning the American Museum of Natural History was opening a temporary exhibition on bird origins, my first instinct was that I had to go. Fortunately, Maryland is in close enough proximity to New York that I was able to make that a reality.

A fair amount of space is devoted to the evolution of avian reproduction, including characteristics shared with their closest living relatives (crocodylians) as well as our understanding of reproduction in Mesozoic theropods. Here is the oviraptorosaur embryo "Baby Louie".

A model of a giant oviraptorosaur nest with a restoration of the probable parent, Gigantoraptor. The dinosaur restorations at this exhibit are (thankfully and expectedly) above average, but a few pennaraptors still suffer from primary-eating feather mites. It's time to stop, please.

The famous "Big Mama", a Citipati preserved brooding on its nest.

An oviraptorosaur with unlaid eggs still in its body cavity! The paired eggs indicate that non-avialan theropods still had two functional ovaries, unlike the single one in modern birds.

A gallery of bird eggs, including both extant and extinct species.

A gallery of pennaraptor skulls and endocasts, showing the evolution of the avian brain. I was glad to see Dr. Eugenia Gold as one of the talking heads on a nearby video screen, considering that her recent research has focused on avian endocranial anatomy. Notice the "bird-o-meter" next to the labels of the fossil dinosaurs, indicating how closely related each one is to modern birds.

A wonderfully-preserved pair of Khaan that were found in close proximity to one another. The wording on the signage was sensibly cautious about interpreting them as a male and female. (Hint: dimorphism cannot be demonstrated with a sample size of two...)

Another excellent fossil, this time of Velociraptor. This may be the "sleeping" Velociraptor specimen I've heard rumors about.

A gallery of furculae. The largest one belongs to Tyrannosaurus.

I was impressed by how up to date some of the displayed information was. Here, recent discoveries of one-way breathing in crocodylians, monitor lizards, and iguanas are used to explain the evolution of the avian respiratory system.

There were a number of life-sized models of representative feathered dinosaurs, including this Beipiaosaurus.

In fact, a virtual parade of life-sized models and partial mounts made up the centerpiece of the exhibit. Here is a fairly nice Velociraptor. (Additionally, I overheard more than a few expressions of surprise from other visitors who were learning that non-avialan dinosaurs had feathers, both a reminder that this fact is not common knowledge outside of the paleontology community as well as real-time demonstration of the value of exhibitions like this one.)

As the largest dinosaurs with direct preservation of feathers, Yutyrannus stole the show.

A fossil cast of Yutyrannus in all its glory.

Some interesting speculation on the presence of feathers in large dinosaurs.

Fluffy ornithischian Tianyulong. Shame about the pronated hands.

An Archaeopteryx that looks like a real animal and not a half-lizard freak. Good job.

A cast of the Berlin Archaeopteryx and the original holotype feather.

An oviraptorid with young. The oviraptorids (there are others not pictured here) were the best models on display, in my opinion. I should have taken more pictures of them.

On the origin of flight, here is an Anchiornis performing wing-assisted incline running.

A cast of "Dave" the (possible) Sinornithosaurus.

A cast of Caudipteryx.

A cast of Tianyulong.

Feathers did not evolve in an aerodynamic context.

This... is one of the few parts of the exhibition that I had issue with. It's fair enough to point out that the developmental homologs of feathers originated long before the evolution of birds, but it does not thus follow that feathers themselves arose at the base of Archosauria (as implied by the accompanying restoration). On top of that, picking Effigia, a pseudosuchian that happens to have several other convergently bird-like characteristics, to clothe in feathers may come across as more than a little misleading. It would be cool if crocodylians were ancestrally feathered. However, we do not have the data to claim they were as of yet.

A lithornithid with fossilized feathers (and Effigia skull at top left).

A cast of Anchiornis. Are we seeing some of the original color pattern on those wings?

Juravenator shows that feathers and scales are not mutually exclusive.

Microraptor represents early experimentation with aerial locomotion in paravians.

Confuciusornis (left) and Xiaotingia (right) may have also had varying degrees of flying ability.

Look, it's Yi!

Jeholornis shows that feathers can function in display, too.

I liked the fact that some space is dedicated to Cenozoic birds as well. Here is another lithornithid.

That's stem-roller Paracoracias on the left and... another lithornithid on the right? My memory fails me on this one.

The skull of Gastornis.

A comparison of flying vertebrates.

An entire wall showing the stepwise acquisition of "avian" traits and the nebulousness of the term "bird". Unfortunately, some workers were repairing the interactive "test how well each dinosaur can fly" game, so I could neither get a better picture of the wall nor observe how the game worked.

The final display case contained a currently unnamed troodont, reportedly soon to be described.

A small gift shop directly followed the exhibition. One of the creatures on this shirt is not a dinosaur. (Surely, it would have made a better tie-in to the exhibit if they had included at least one bird on the shirt?)

Half of these titles belongs. The other half... doesn't.

Despite some minor quibbles about life restorations and feathered pseudosuchians, I found "Dinosaurs Among Us" to be excellent. It presents our understanding of avian origins in an incredibly current and multifaceted manner, and there is little I would add or change if I were in charge of making such decisions. Check it out if you have the chance! (It is open until January 2nd of next year.) It was well worth the long train ride to and from New York, and that's a trip I wouldn't make again in a hurry.

... What do you mean, there is also a pseudosuchian exhibit now?

Thursday, June 2, 2016

Maryland Zoo in Baltimore

Living in the shadow of the much larger and admission-free National Zoo, it's easy to see why the Maryland Zoo in Baltimore is frequently overlooked. Having had the chance at last to visit it, however, I can confirm that it contains a few gems and has sufficiently little overlap with the National Zoo to make it at least worth considering as a travel destination.

For reasons unknown to me, the bulk of the zoo's exhibits are found some distance away from the entrance and need to be reached either on foot or via shuttle. One of the few displays that can be found near the entrance is a well-populated black-tailed prairie dog enclosure. A good choice for first impressions, as the ground squirrels were quite delightful, particularly the juveniles.

Another nearby display houses African birds, among them this obliging Abyssinian ground hornbill. The real dinosauroid.

The main portion of the zoo is divided into three loop trails. The shortest of these trails has a focus on arctic animals, including polar bears and ravens. Most memorably, it took some time for me to get even a halfway decent shot of this arctic fox.

My friend Ben found this wild brown snake on our way to the next loop trail.

The second loop trail featured local Maryland wildlife, including an aviary with many native bird species. Here is a green heron.

Diving ducks are always charming, and these ruddy ducks were no exception. As a bonus, we got to see the males in their breeding colors, an unlikely prospect in the wild considering they only winter here.

One of the ruddy ducks feeding alongside a pair of wood ducks.

A little blue heron.

A sandhill crane.

A turkey vulture.

Wild snakes were out in force that day, as we saw three northern water snakes (one not pictured) chilling in the aviary.

Not one of the wild snakes we saw, but a captive copperhead.

Some box turtles had a surprisingly spacious exhibit (which is not evident from my photo).

A pair of trumpeter swans.

The final and longest loop trail is devoted to Africa. Likely the best exhibits in the zoo are found here, including a nice display housing sitatunga and these African crowned cranes.

We observed these chimpanzees using sticks to pull surrounding leaves and bamboo shoots into their enclosure for consumption.

I was surprised to see okapis at this zoo. They share a giraffid house with giraffes, though their exhibits are unfortunately quite plain.

More aesthetically pleasing was this grassy habitat for addra gazelles and saddle-billed storks.

An African aviary nearby contained blue-bellied rollers that were more than willing to show off their acrobatic flying style.

A pair of Von der Decken's hornbills.

A pair of African pygmy geese, among of the smallest waterfowl in the world. According to exhibit signs, there is also a blue duiker living in the aviary that decided to be a no-show. The omnivorous tendencies of duikers make me wonder how safe it is to keep one with birds.

A wild spotted sandpiper hanging out in the rhinoceros exhibit. (It probably says something about me that I took a picture of a common bird but not the rhino...)

A small, easily-missed display is home to some very delicate-looking Kirk's dik-diks.

Living alongside the lap-sized antelope are demoiselle cranes.

The centerpiece of the zoo is a large pool for black-footed penguins. Also present is a volant species of diving bird that lives in the same region in the wild, the white-breasted cormorant.

We passed by the penguin pool just in time to see them being fed. A wild herring gull hung around nearby in hopes of getting some scraps.