A trip to the dentist's lab

3 March 2010. Edmonton, AB, Canada

Last Friday I had a pleasant trip to the dentist's office. It was pleasant only because I was not the one being examined!

With the helpful pointers of the graduate students at the University of Alberta Laboratory of Vertebrate Paleontology, I recruited the generous help of scientists at the University of Alberta Department of Dentistry with the CT-scanning of a few mammal skulls.

[it was crucial to place the specimen at just the right height to be scanned within the window of the sensor.]

To test-run the modeling protocol that I use here on the University of Alberta campus, I borrowed a few modern carnivore skulls from the University of Alberta Museum of Zoology to scan. One of the specimens was a genet skull from Africa, about the optimum size to be scanned with the medical dental scanner that we used.

[the medical CT scanner is normally used for orthodontic patients; specimens had to be propped to head level of a sitting human.]

The resolution was excellent for the type of research that I do; the skulls were scanned into image slices of 0.25 mm thickness. Test models are being constructed to analyze the biomechanics of mastication from the scan data.

[the data acquisition software was rather user-friendly and could be learned in less than 10 minutes.]

~Jack


Thanks are due to my wife Juan whose assistance made the scanning session go smoothly.

New bird sighting added to list

9 February 2010. Edmonton, AB, Canada.

1115. This morning, as I walked out of Dr. Mark Wilson's systematics lecture towards the Biological Sciences Building on the University of Alberta campus, I heard an unmistakenable call coming on one of the tree branches high above me...

It was a warm and energetic song of the Eastern Phoebe, Sayornis phoebe, and not the dry cracking call of the black-billed magpie that one is accustomed to during the northern winter. Phoebes are tyrant flycatchers (Family Tyrannidae) that catching insects in mid-air with acrobatic maneuvers.

They are also the sure signs of spring in this part of North America; in central and northern Alberta and other regions of the northern plains, these insectivorous birds are summer visitors, leaving for warmer southern areas at the end of each fall. Their call this morning is a welcome one, as snow still covers the lawns on campus, but no longer is the wind chill bitter and sharp. Warmer weather is upon us, and longer days are leading us into the green season, a change not so distinct in California!

Hooray for spring!

~Jack

New study by LACM paleontologists

29 January 2010. Natural History Museum of Los Angeles County.

A study of new material of the nimravid ("false sabertooth") Barbourofelis whitfordi by LACM paleontologists has just been published in the January 2010 issue of the Journal of Vertebrate Paleontology.

This paper describes an almost complete dentition of the most basal species of the last-remaining nimravids in North America. Barbourofelis first appeared in North America during the early Clarendonian North American Land Mammal Age (NALMA), and persisted until the Hemphillian NALMA. The approximate duration of the genus is 5 million years, between 12 and 7 million years ago.

The new fossils were discovered in the Dove Spring Formation, located in gorgeous Red Rock Canyon State Park in the Mojave Desert of southern California. The inspiration and awe that majestic California State Parks give to us rival their rich scientific resources! Paleontologists are still being humbled by what the ground hides beneath its surface, even after more than 100 years of geologic and paleontologic study in the area.

The discoverer of the new fossils is a long-time museum staff, associate, and supporter Mr. Kamaron Sardar, also a protector and server of our city.