Knowing the Nose

A recent study published online, reexamines the radical idea that Diplodocus had a long trunk, an idea first proposed by Robert Bakker in his 1986 book on dinosaurs. Although the idea has not received much support, in large part because of the absence of observable muscle scars on the skull bones around the nose, several investigators took an independent look by reexamining the relative size of the facial nerve, as indicated by the bony opening that it passes through. The facial nerve along with the trigeminal nerve innervates the nose region in most vertebrates, thus a larger sized facial nerve would indicate a larger nose. In relation to the size of the opening in elephants, Diplodocus had a very small opening for the facial nerve. Although, one would like to see a more quantative approach to this question, at least support leads away from a long nosed Diplodocus.


Knoll, F., Galton, P.M., and Lopez-Antonanzas, R. (2006) Paleoneurological evidence against a proboscis in the sauropod dinosaur Diplodocus. Geobios
Article in Press

Mesozoic Mammals Fight Back

The Mesozoic was a dangerous time to be a mammal, and a new study by Hurum et al. (2006) show that they just didn't yield to becoming simply Dinosaur snacks. Using a spur on the ankle, Mesozoic mammals, such as multituberculate Catopsbaatar fought back against dinosaur predators by secreted poison from a gland and imbedding it into the skin of a predators.

Amazingly living monotremes, such as the platypus still retain this ankle spur.
The ankle spur is composed of three parts, the os calcaris (the base), the ossified cornu calcaris (the core), and the cornu calcaris, the keratinous covering. All marsupials and placental mammals have lost this structure.

Hurum, J.H., Luo, Z−X., and Kielan−Jaworowska, Z. 2006. Were mammals originally venomous? Acta Palaeontologica Polonica 51 (1): 1–11.

The Crowned Dragon

Exhibiting a flashy cranial crest, a new Jurassic dinosaur from the Junggar Basin of China provides researchers a unique view into the origin of Tyrannosauridea, the family that contains the fameous tyrant king itself, Tyrannosaurus rex. Instead of a massive 6 foot skull, the realively small new dinosaur (Guanlong) poccesses a complex ornamented "crown" formed by the fusion of the paired nasal bones, and extends posteriorly to cover most of the skull roof. This cranial crest houses a large pneumatic fenestra that served an unknown purpose. However, since the skull lacks osteologic correlates to thermoregulatory functions, the cranial crest and fenestra likely served a role in species recognition or sexual display. The new dinosaur is reminiscent of the closely related North American dinosaur Ornitholestes. However, Guanlong exhibits a number of characters that place it near the base of the Tyrannosauridea.


Xu, Xing, Clark, J.M., Forster, C.A., Norell, M.A., Erckson, G.M., Eberth, D.A., Jia, Chengkai, and Zhao, Qi. 2006. A basal tyrannosauroid dinosaur from the Late Jurassic of China Nature 439, 715-718 (9 February 2006) doi:10.1038/nature04511

Out of Africa

Revolutionary studies using molecular data to understand the phylogenetic relationships between living species and populations strengthen ideas about fossil relationships. The idea that Elephants, Hyraxes, and Elephant Shrews (the "Afrotheria") share a common ancestor came about by these revolutionary studies (Murphy et al 2001). Since then paleontologists have been trying to test this idea by finding intermediate species in the fossil record that show similarities. One group that may hold the answer is the louisinine mammals. These mammals are known primarily from the Paleogene of Europe and have previously been grouped with the North American hyopsodonts, such as Hyopsodus. New fossils of the ankle show characteristics with elephant shrews and hyraxes. They now should be regarded as afrotherian immigrants from Africa. The question still remains whether North American hyopsodonts are all one group, or whether some belong to the Afrotheria as well.

Tabuce, R. Antunes, M.T., Smith, R. and Smith, T., 2006. Dental and tarsal morphology of the European Paleocene/Eocene "condylarth" mammal Microhyus. Acta Palaeontologica Polonica 51 (1), p. 37-52.

See also: Murphy, W.J., Eizirik, E., O Brien, S.J., Madsen, O., Scally, M., Douady,
C.J., Teeling, E., Ryder, O.A., Stanhope, M.J., and de Jong, W.W. 2001. Resolution of the early placental mammal radiation using Bayesian phylogenetics. Science 294: 2348–2350.