Monday, October 29, 2012

More Monumental Discoveries

Three collaborative field teams—all part of the Kaiparowits Basin Project—have just wrapped up their 2012 explorations in the wilds of Grand Staircase-Escalante National Monument (GSENM), southern Utah. The trio of paleontology crews, all working in rocks of Upper Cretaceous age, came from the Denver Museum of Nature and Science (DMNS), the Natural History Museum of Utah (NHMU), and from the Monument itself. The results? More dinosaurs. More crocs. More plants. And plenty of other amazing Late Cretaceous fossils to add to the ancient treasures unearthed over the past dozen years [1].

The GSENM crew, led by Monument Paleontologist Alan Titus, had another spectacular year of discoveries, including an ankylosaur skull with partial skeleton from the Wahweap Formation, and a variety Kaiparowits Formation finds, including multiple duck-billed dinosaurs (aka hadrosaurs). The NHMU crew, under Mike Getty's guidance, spent most of the fall working on a pair of Alan’s hadrosaur discoveries. One of these has abundant skin impressions that seem to differ from anything we’ve seen thus far. The other includes a well preserved skull.

The Kaiparowits badlands of Grand Staircase-Escalante National Monument
Alan and his crew also excavated yet another skull and partial skeleton of Parasaurolophus in 2012. We now have on the order of six Parasaurolophus skulls from the Monument, by far the largest collection of this tube-crested duckbill known anywhere. At the end of the season, the Utah crew tried to get into a more remote site to work on an exceptionally preserved lambeosaur skeleton (perhaps another Parasaurolophus), but torrential rains forced the crew to abandon the field area. Nevertheless, collaborator and head hadrosaur researcher David Evans (whom I visited at the Royal Ontario Museum just last week) is very excited by the sheer bounty of great fossils emerging from GSENM.     

After giving a talk at the Escalante Arts Festival on September 28th (and seeing Alan Titus’ sensational cover band “Mesozoic” rock the house the following day), I spent some time working with the Denver field crew. The DMNS camp included interns, museum staff, and plenty of enthusiastic volunteers, all capably led by paleobotanist Ian Miller and vertebrate paleontologist Joe Sertich. They too had more fossils than they could handle.

At one extensive leaf locality, Ian directed a large-scale census, documenting over 1000 specimens. Meanwhile, Gussie, one of the DMNS interns, checked every leaf for insect damage, collecting dozens of examples for subsequent research. Although no body fossils of insects have been discovered in the Kaiparowits Formation, Gussie’s study of the different damage types on leaves should give us some sense of the insect diversity that lived alongside these Cretaceous dinosaurs. As a devoted “dinosaur guy,” I learned a lot splitting rocks in a leaf quarry. And I had to admit, with the rapid pace of fossil discovery (one every few minutes or so), paleobotany quarrying can be addictive!

 A Fossil Leaf Quarry

While half the crew dug leaves, the other half dug bones. Two hadrosaur quarries about 50 feet apart took the bulk of the effort. Like many of our best specimens, one of these is preserved in concrete-like sandstone, requiring abundant use of a rock saw just to get down to the bone layer. Some of the fossils will require a helicopter airlift, but for this fall we were able to haul out a number of specimens in backpacks and on a stretcher. (Yes, it's seems a little odd to "rescue" a long extinct dinosaur—piece by piece—from the badlands using a stretcher, but it works.) Together with my long time friend Dale Penner, I also checked out a promising new crocodile site. We excavated just enough to demonstrate that this locality (found by Joe) has great potential.

Ian (background) and Gussie (foreground) looking for insect damage 

After I departed, Ian and crew returned to a leaf site in a southern pocket of the Kaiparowits that we’ve dubbed “the Lost Valley.” The name derives from the remoteness of this place as well as the fact that it is “guarded” by sheer cliff walls on all sides. At this Lost Valley quarry, the DMNS crew uncovered many beautiful fossilized leaves, cones, and flowers, including plenty of previously unseen varieties. Thanks to the abundance and preservation of these plant parts, as well as the way the shale fractures into large chunks (preserving whole leaves), Ian is convinced that this is one of the best Mesozoic plant sites he’s ever seen!

Joe Sertich doing a little rocksawing

Not far away, Joe Sertich and crew worked on a newly discovered site with ceratopsian skull, vertebrae, and limb bones that may belong to the 15 horned wonder known as Kosmoceratops. While working the quarry, one of the volunteers, actor-photographer-weatherman-and-all-round-good-guy Billy Doran walked to the other side of the same hill and found more ceratopsian bones, including skull parts from a much bigger animal eroding out of the hill at what appears to be the same layer. If so, this site may just represent one of the first horned dinosaur “bonebeds” that we’ve found in GSENM. These sites, some of which contain dozens of individuals in formations up north in Alberta and Montana, have thus far been rare to nonexistent in Grand Staircase, so we will be excited to dig in again next spring!

Carrying dinosaur bones from the badlands on a stretcher

Finally, although we have found plenty of dinosaur eggshell fragments, and even the occasional large piece of fossilized egg, so far the dinosaur nests have eluded us in GSENM. Till now anyway. Joe just informed me today that his group came across a possible nesting horizon, with many big chunks of shell along with tiny bones and teeth that could well be embryonic. However, like the Utah crew, the Denver team was forced to escape before the big rains hit (or, more accurately, while they were hitting), so this is another site that we will have to wait until next year. So stay tuned for more updates!

1. Sampson, S. D. 2012. Dinosaurs of the Lost Continent. Scientific American, March, 2012: 40-47.

All photos taken by the author while in the field, September and October, 2012.