The quest for the Qaidam hyena cranium

Having introduced the research background of our work in the Qaidam Basin of the Tibetan Plateau (Part I), we will now tell the story of one of the most important fossil finds (well at least in Jack's mind) during the 2007 field season.

We use the Linnean hierarchy to describe the evolutionary position of each fossil species, for example we introduce the Qaidam hyena cranium, the focus of this post:

[hierarchical position - name - author - year of publication]
-Class Mammalia Linneaus 1758
--Order Carnivora Bowdich 1821
---Family Hyaenidae Gray 1869
----Genus Adcrocuta Kretzoi 1938

This hierarchical arrangement of information tells us that the genus of interest here (Adcrocuta) is a member of the hyena family (as opposed to the dog family for example), which belongs in the group of carnivorans (as opposed to primates for example), which is one of the mammal orders (as opposed to reptiles, for example).

Jack (Zhijie) discovered this specimen in the Shengou area on 29 July, 2007, at approximately 5 pm. We had been working for several days in the Shengou area, splitting the expedition crew between a mammal prospecting team at the main locality area, and a fish collecting crew at the Naoge area across the valley. The following is an account of Jack's memorable day:

The day started out very gloomy. We had been prospecting within a 1 km radius of the camp site for the past couple of days. But on 29 July a small crew (Qiang Li, Gary Takeuchi, Jack Tseng) was transported a few kilometers northwest to examine new areas.

We ascended the southwest dipping strata from deep down in the wash where our vehicle dropped us off. The wind was gusty, but a welcomed companion as a hiatus in the wind meant an opportunity for the Shengou mosquitoes to attack us. Li Qiang headed along strike in the lower part of the section, and Gary and I went further upsection, collecting a fossil turtle shell along the way.

We made it just up to a small plateau upsection before the sky started sprinkling. It was getting cold. However, we still needed to tread higher grounds to search for fossils, in addition to making the trek back to camp on foot. I pulled out my rain-jacket and gloves, and continued upward.

Eventually the strata flattened out enough that there are simply no more suitable exposures for prospecting. That's when we started back in the direction of camp. We came to another gulch which runs perpendicular to the dipping sections of rock. The bottom of the gulch had desertified, so we descended into a large sand dune. The fun part was getting back up to the other side of the gulch through the sand dune.

As it was near the end of the work day, we slowed our pace and hiked leisurely across the rolling terrain, in the direction of our camp.

[to be continued...]

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