Just add water: a mammal fauna in minutes!

6 September 2008. Keluke Lake, Olongbuluk Mountains




Today was a long day. I had to take a nap.

[screen washing along Keluke Lake]

After washing 103 bags of sediment yesterday, we finished the remaining 17 bags in the morning. In the mean time, Xiaoming and Dr. Xie Guangpu relocated the site of Birger Bohlin's field photogaph of the Keluke Lake area, and reproduced the photograph with a digital camera.

[group photo]

After meeting for lunch and a group photo, we split up again. One team went to measure the geologic section of the Chuanshuiliang area (where we camped for the past week). I went prospecting, and found an entire large mammal fauna in a matter of 20 minutes.

[first batch of fossils: top right is questionable chalicothere]

Some of the new material added to our current collection include the lower jaws of a chalicothere, a group of large extinct herbivorous mammals. I also found a partial jaw that might belong to an entelodont, an extinct group of large, perhaps omnivorous ungulate mammals.

[second batch: horns at top center, partial antelope skull at bottom right]

But on top of those discoveries, I found a partial lower jaw of a gracile hyaenid, what I think might be a medium sized species of Hyaenictitherium, a late Miocene hyena resembling a small wolf or large jackal.



That makes two different hyena occurrences discovered in the past week, a pretty good (great) week, I would say.

[the two hyaenids found so far: Hyaenictitherium at top, ?Percrocuta at bottom]

Tomorrow we are moving our base of operations up-slope to Kunlun Mountain Pass, our highest fossil locality at over 14,700 feet in elevation. We are gearing up for snow.



Jack

The past and present in Chaidamu Basin

4 September 2008, Keluke Lake, Qinghai Province


Today was a short day, allowing me to put up more photos.

[sunrise]

Our gasoline-powered water pump is broken; we collected 120 30-lb. bags of sediment from the Huaitoutala area, and transported them to the lakeside. Without a working pump we returned to Delingha to get the pump fixed.

[collecting sediment in the Huaitoutala area; note the high tilting angle of the strata (rocks), characteristic of this anticline]

Some of you asked about what the present day environment is like here; we are working in a highland basin with nearly all localities above 8,000 feet elevation. The landscape is overall as you would see in the Mojave Desert in southern California. One major difference is that there are no trees (or tall shrubs) anywhere near shoulder height. The plants are short and compact, probably a common appearance to preserve water.



There is almost no flowing water besides two large lakes in the basin; somehow, the mosquitoes still find enough moisture to proliferate, making them the most common insect here (yippie...)



In terms of larger wildlife, the Keluke Lake is frequented by shoredbirds of all sizes; from large ducks to terns to sandpiper-sized critters. Large unidentified vultures are often seen circling overhead during mid-day. Sand lizards are very common, and run under your foot with every hill you hike.

[Keluke Lake]

For people interested in large predators and their prey (no bias here), the most common carnivoran here is probably the fox (possibly red fox, Vulpes vulpes). Their tracks and scats are everywhere. Once in a while I find remnants of rabbits, antelopes, and pigs in the wash between hillsides. Wolves are a rare sight now, but they still exist here.

[a partial rabbit foot some carnivore had chewed on; it was too fresh to put on my pack for good luck]

By far the most common large fossils we discovered in the past week are horncores from a variety of antelope-like animals: straight horns, curving horns, twisting horns, short stubby horns, thick and enormous horns, to name a few. The late Miocene fauna in this area was very diverse, and the abundance of these fossil creatures would have rivaled the Serengeti in Africa.

[rhino tibia]

[a complete horncore embedded in sandstone]

We also collected several large bones of rhino and elephant, including a rhino radius/ulna discovered while I was writing one of the blog entries.

[a partial elephant tusk fossil, about 1.5 feet in length]

[another elephant tusk, very broken]

We have catalogued 94 fossil localities in the past week's work; the abundance of fossils here reflect the journal entries of the great explorer Birger Bohlin, who visited the Keluke Lake area in the 1930s.

[partial fossil fish skeleton, note vertebral column]

Day time high temperature has been around the 70's F; overnight temperature reaches below freezing. Our lips are chapped from the dry gusts, our faces are covered in fine Miocene sandstone dust, but our crates are filled with new and exciting fossils which will hopefully reveal to us a better picture of the past environment and biodiversity of this present day high desert.

[making a field plaster jacket]

The morale stays high as we prepare to enter Eboliang in a few days, by far the most desolate place we will work in across the entire basin. More to come on that...



Jack

Out of the desert (for now)

3 September 2008, Delingha, Qinghai Province

We just came out of a 5-day stay at the foot of the Olongbuluk Mountain. Pictures speak better than words, so without much delay:

[our vehicles driving into the field area]

[setting up camp]

[fossil prospecting]

[crew heading out in the brisk morning]

[Olongbuluk area]

The Olongbuluk area we were working in is of late middle Miocene to late Miocene in age; the fossil-producing strata are fluvial sandstone deposits ranging from half a meter to two meters in depth. The entire area forms a syncline structure with most fossiliferous deposits north of the structural axis. The mammal and fish fossils are coming out of moderately sorted sandstone or iron-rich resistant sandstone of a deep purple color.

[on the way out of the field area, crew looking tired]

Tomorrow we will begin sampling sediment to screen wash for microfossils (rodents); after an evening's rest, we will switch gears and shovel dirt for a day. We hope to collect close to one metric ton's worth of dirt to screen wash with water.

[acting silly in front of Olympic mascots]

Speaking of hyenas, Andie, I am not sure whether all hyaenids lack clavicles (I am guilty of being a head hunter...I have not seen many fossil hyena skeletons during my study yet, but given the likelihood of most hyaenids being capable hunters, I would expect them to have very reduced clavicles or total absence in order to increase range of forelimb motion during running). I will get back to this question with a better answer.

One of our crew members, Dr. Qiang Li, discovered a partial lower hyaenid jaw on 31 August; the jaw has a canine and a lower third molar preserved. We are not sure of the identity of this specimen, but given its large size it could be Percrocuta, one of the rarer hyenas of the Old World. The true identity will be revealed once I compare hyaenid specimens in Beijing.

Jack

Hello from Olongbuluk

28 August 2008

1940 hrs. I am sitting on top of a hill overlooking the Tuosu Lake, in Qinghai Province just southwest of the town of Delingha. The sun is setting to my right, and I can see the passing clouds turn a bright orange as they pass the sun.

From the snowy peaks and the bone-chilling breeze, we know that autumn has arrived on the Tibetan Plateau; the top of the hill is cold (probably in the mid-50s F), and with each gust of wind my fingers struggle to type on the keyboard.

We drove into the structurally complex area of Olongbuluk with three days of food and fuel. After setting up base camp in a pocket between two hills to shelter us from the wind, we attempted to cook dinner. Our gasoline stove was acting up and the fire would not stay lit. Finally we got enough heat to cook some meat, which we ate with zeal along with some pancakes and tomatoes.

I had been making glue for our first day of fossil prospecting tomorrow. I mixed 50 grams of acryloid crystals with 100 grams of acetone, and diluted the concentrate to make thin consolidant.

It is now after dinner; songs are being played from the car stereo, as the crew members chat around the campsite. Dr. Xie Guangpu is calling me now, he has just found a partially embedded elephant foot bone on the hill adjacent to where I am sitting.

Business is at hand; I must go stabilize our first large fossil and plan for a possible jacketing job tomorrow morning.

From China, with love,

Jack