Wednesday, December 12, 2012

Name that skull

The Smithsonian National Museum of Natural History has a great website on human origins. It is a treasure trove of information on human and primate evolution including a 3D digital collection of many artifacts and fossils. My favorite feature is the Mystery Skull Interactive which gives you a set of skulls and asks you to identify them by comparing them side-by-side with skulls that are already known. It is a great way to highlight the meticulous attention to detail that paleontologists and anthropologists need to have to be able to correctly identify fossils.

Monday, December 10, 2012

Catfish preying on pigeons on land

There are plenty of examples of terrestrial vertebrates feeding on aquatic animals, but it is unusual for bony fish to go after animals on land. Some marine predators like sharks and cetaceans, for example, will eat birds in the water and orcas can jump onto pieces of ice to get at seals, but this is the first example of a fish that essentially beaches itself to get at prey on land. As the authors of the study note, these catfish are not native and so this may be an example of a predator taking advantage of a new food source in a somewhat 'artificial' setting.

Tuesday, November 13, 2012

Dolphins can sense electric fields

Electric fields travel much farther through air than through which is why bony and cartilaginous fishes have exquisitely sensitive electroreceptors but most tetrapods have lost them. Known exceptions are some partially or fully aquatic tetrapods like some amphibians and monotremes. This research shows that dolphins can also be added to the list. The study found that the dolphins have little pits along their face called vibrissal crypts that resemble the ampullae that fish use for detecting electric fields. They also showed that the dolphins could detect electric fields by training them to respond to an electrical signal in the water. This is another example of convergent evolution because the vibrissal crypts are not homologous with the ectroreceptive organs of fish or even of the monotremes. Instead, they are equivalent to the pores that whiskers grow from in other animals. Whiskers are extremely sensitive sensory organs in many animal such as felines and rodents. It seems that in the course of dolphin evolution, the whiskers were lost but the sensory apparatus was retained and co-opted for a new purpose.

The vibrissal crypts (Proceedings of the Royal Society B
Electroreception in the Guiana dolphin (Sotalia guianensis
Proc. R. Soc. Bvol. 279 no. 1729 663-668

Tuesday, October 30, 2012

New insights into the origin of air breathing

It is fairly well established that the common ancestor of tetrapods and bony fish had air-breathing lungs, but no one really knows how air-breathing really evolved in the first place. This study shows that lampreys have neural circuitry for detecting  carbon dioxide and 'coughing' water out of their lungs when it gets too high. This would be a prerequisite for a tidal breathing system.

Wednesday, October 24, 2012

Small World

This has little to do with vertebrate zoology per se , but I love microscopy and this contest always has some awesome images. The bat embryos are particularly adorable.
Nikon Small World 2012 Photomicrography Competition

The Hidden Life of the Cell

This video has some excellent animations of various cellular processes. It is also narrated by Dr. Who:
The Hidden Life of the Cell

Wednesday, October 10, 2012

New dinosaur species described with quills, beak, fangs

From National Geographic:
If a mad scientist mixed the DNA of a warthog, a chicken and a porcupine, it might look something like this. At the link there is also a neat video showing how they reconstructed the head from the skull fossil.

Monday, October 1, 2012

New Species Discovered in Peru
New species are discovered almost every day around the world, but it is unusual to find so many mammals at the same time. Keep in mind that 'new' only means 'new to science'. The locals have probably known about these species for generations. Also, note that they discovered two species of shrew, but one is a marsupial shrew while the other is a placental shrew. The caption for the small-eared shrew refers to the marsupial shrew as its 'relative'. They are related of course, but the small-eared shrew is more closely related to the monkey and porcupine than it is to the marsupial shrew.

Thursday, August 23, 2012

The first week

During the first week of class we spent a lot of time talking about the basics of evolution and the history of evolutionary biology. Much of the material came from this website: especially here and here. The whole site is a great resource on evolution and basic concepts in zoology.

Tuesday, July 24, 2012



This blog will hopefully serve as a useful resource for students taking Vertebrate Zoology at OSSM. I will occasionally post about news articles and published scientific research related to the topics we cover in class, plus any other items from around the web that I find interesting. Feel free to leave comments or suggestions.