Starting the hole

RMDRC 06-009 “Cap’n Chuck” was the first mosasaur I ever found. It’s a specimen of Platecarpus “ictericus” (sorry Takuya, haven’t made the species switch yet) from the upper chalk of Logan County, about 83 million years old. I spotted a single dorsal vertebra sticking out of a vertical gully wall, about 12 feet above the gully bottom. Don’t ask what I was doing looking up there. My boss, Mike, loaded Jacob and I into the bucket of the bobcat and lifted us up to see if there was anything else there besides the single vertebra. Yep! we discovered the back of the skull, but since it was late October and in the low 50s (with drizzle coming in and lots of wind) we decided to secure the site till the next spring.

Jack-hammerin

In April of 2007 we returned, with a fancy new mini jackhammer that Mike had bought over the winter. Holy moly that thing saved us a lot of time.

We made this big of a hole in 3 days

Do you see the skull?

It turns out field mapping in the chalk is kind of a tough thing to do. The chalk gets all over everything and generally makes life miserable. It’s best to save it for the lab. The skeleton was preserved very well, missing the end of the tail. Quick measurements of elements give us a total length of about 23 feet, which is pretty dang big for a Platecarpus.

Main jacket flipped and prepared. Things are much easier to see.

Once show-prepped in the lab it was decided that Cap’n Chuck was complete enough to restore in 3d (most exploded skulls are good candidates, there’s less crushing distortion). That meant pulling every individual bone out of the jacket and cleaning it completely. This enabled us to get a good look at some rare parts like the interclavicle and ear cartilages. Hopefully we’ll be able to start restoration sooner or later!

Laid back

You ever get the feeling you’re being watched?

This past summer during beer week in Montana I found a small shard of tyrannosaur tooth sticking out of a lag deposit. I suggested to one of our guests, Terri, that she could spend some time excavating it. Turns out she discovered that the tooth was still connected to a chunk of jaw. Unfortunately digging it out was a bit of a chore since the sandstone got really hard really quickly. It did clean up nicely though, and will be going on display sometime today.

Tyrannosaur maxilla and tooth

Some progress is being made on Pete III, our challenging Daspletosaurus torosus, also from Montana. This huge 70 pound monstrosity of a jacket contained just one spindly rib. That and lots of sandstone. Whatever, it’s off the shelf now and nearly in the clean room.

There’s the rib!

We’re not all about preparing partial dinosaur bones though. This Pteranodon sternbergi metacarpal was pulled from the lower chalk in western Kansas a few years back. Should have been prepared years ago.

Isolated bones are so pretty

]]> http://dinosaursanctuary.com/2011/03/small-projects/feed/ 4 http://dinosaursanctuary.com/2011/03/more-lambeosaur-fun/ http://dinosaursanctuary.com/2011/03/more-lambeosaur-fun/#comments Thu, 10 Mar 2011 20:58:00 +0000 anthony http://dinosaursanctuary.com/2011/03/more-lambeosaur-fun/

This week we’ve had a chance to begin work on the skull material recovered from RMRDRC 07-020 “Joyce”, from the upper Judith River Formation of Fergus County, Montana. The material is typical for the Judith river… SOFT. We’ve begun utilizing the technique that I wrote about for the first FPCS at Petrified Forest National Park, in stabilizing he matrix and bone with low-strength adhesive (PB 4417) before air abrading the material. The results are great! I’d like to share a few pics of the first jacket we have prepared, and if anyone wants to take a well educated stab at the identity of the lambeosaurine, have at it!

Present is the right dentary in lingual view, as well as a quadrate and partial quadratojugal. 31 rows of teeth are present in this dental battery.

It’s always an exciting time when we come to the end of a project. Mostly because it’s one of those rare times where we’re finished with something. This week we’re finishing the right leg from an exceptionally big lambeosaur (crested duckbill dinosaur) that was discovered this past summer in the Judith River Formation by Dr. Kraig Derstler. We were very excited at the time about the find since big articulated dinosaur legs usually lead to big articulated more complete dinosaurs. Usually.

Digging revealed that it was highly likely that the entire skeleton was present at one time in the late Cretaceous, however everything but this right leg (animal was probably laying on its right side) was eroded away during the Campanian. Oh well, it stings a little less when you know you’re 78 million years too late.

We had help from some great ranchers and their newfangled power ATV things getting the specimen out of the bottom of the uncharacteristically wet gully. Without them, the leg would still probably be there riding out the winter. Above are ranchers Matt Wickens and Kerry Simac, with “field chef” Peter checking his gear. Below Jacob is pointing to the specimen, while rancher and dino finder extrordanaire Larry Tuss rests. I’m just sorta holding up the “outfit” as they call vehicles in Montana.

A few months later this is the result. A reasonably complete prepared leg. Missing the fibula, astragulus and calcaneum due to erosion, and the ungual on digit IV. The monster is 11 feet long (3.36 meters). Biiiig.

Assembly of the body of the first cast is done! Just detailing and the skull to go. Today we decided to see what it looks like with the skull on the body. Let’s just say we were a bit surprised with the size of the animal that resulted. Here April and Todd do the honors!

A quick update from the last post. Progress on the Terminonaris is being made on the two prototype articulated mounts. All molding except the skull is finished and all parts are poured. The first mount even has an arm! That should get people excites, since we all know people love pointy bits. Just legs, coracoids and a skull to go. Please excuse the clutter in the shop!

“What Should Everyone Know About Paleontology?”

General

• That rocks are produced by various factors (erosion -> sedimentation; metamorphism; volcanic activity; etc.)
• That rocks did not form at a single moment in time, but instead have been and continue to be generated throughout the history of the planet.
• That fossils are remains of organisms or traces of their behavior recorded in those rocks.
• That rocks (and the organisms that made the fossils) can be thousands, millions, or even billions of years old.
• That the species discovered as fossils, and the communities of organisms at each place and time, are different from the same in the modern world and from each other.
• That despite these differences that there is continuity between life in the past and life in the present: this continuity is a record of the evolution of life.
• That we can use fossils, in conjunction with anatomical, molecular, and developmental data of living forms, to reconstruct the evolutionary pattern of life through time.
• That fossils are incomplete remains of once-living things, and that in order to reconstruct how the organisms that produced them actually lived, we can:
  • Document their anatomy (both gross external and with the use of CT scanning internal), and compare them to the anatomy of living creatures in order to estimate their function;
  • Examine their chemical composition, which can reveal aspects of their biochemistry;
  • Examine their microstructure to estimate patterns of growth;
  • Model their biomechanical functions using computers and other engineering techniques;
  • Investigate their footprints, burrows, and other traces to reveal the motion and other actions of the species while they were alive;
  • And collect information of the various species that lived together in order to reconstruct past communities.
• However, with all that, fossils are necessarily incomplete, and there will always be information about past life which we might very much want to know, but which has been forever lost. Accepting this is very important when working with paleontology.
• That environments of the past were different from the present.
• That there have been episodes of time when major fractions of the living world were extinguished in a very short period of time: such data could not be known without the fossil record.
• That entire branches of the tree of life have perished (sometimes in these mass extinction events, sometimes more gradually).
• That certain modes of life (reef formers, fast-swimming marine predators, large-bodied terrestrial browsers, etc.) have been occupied by very different groups of organisms at different periods of Earth History.
• That every living species, and every living individual, has a common ancestor with all other species and individuals at some point in the History of Life.

Specific

• Life first developed in the seas, and for nearly all of its history was confined there.
• For most of Life’s history, organisms were single-celled only. (And today, most of the diversity remains single-celled).
• The evolution of photosynthesis was a critical event in the history of Earth and Life; living things were able to affect the planet and its chemistry on a global scale.
• Multicellular life evolved independently several times.
• Early animals were all marine forms.
• The major groups of animals diverged from each other before they had the ability to make complex hard parts.
• About 540 million years ago, the ability to make hard parts became possible across a wide swath of the animal tree of life, and a much better fossil record happened.
• Plants colonized land in a series of stages and adaptations. This transformed the surface of the land, and allowed for animals of various groups to follow afterwards.
• For the first 100 million years or so of skeletonized animals, our own group (the vertebrates) were relatively rare and primarily suspension feeders. The evolution of jaws allowed our group to greatly diversify, and from that point onward vertebrates of some form or other have remained apex predators in most marine environments.
• Complex forests of plants (mostly related to small swampland plants of today’s world) covered wide regions of the lowlands of the Carboniferous.
• Burial of this vegetation before it could decay led to the formation of much of the coal that powered the Industrial Revolution and continues to power the modern world.
• While most of the coal swamp plants required a moist ground surface on which to propagate, one branch evolved a method of reproduction using a seed. This adaptation allowed them to colonize the interiors, and seed plants have long since become the dominant form of land plant.
• In the coal swamps, one group of arthropods (the insects) evolved the ability to fly. From this point onward insects were to be among the most common and diverse land animals.
• Early terrestrial vertebrates were often competent at moving around on land as adults, but typically had to go back to the water in order to reproduce. In the coal swamps one branch of these animals evolved a specialized egg that allowed them to reproduce on land, and thus avoid this “tadpole” stage.
• These new terrestrial vertebrates—the amniotes—diversified into many forms. Some included the ancestors of modern mammals; others the ancestors of today’s reptiles (including birds).
• A tremendous extinction event, the largest in the age of animals, devastated the world about 252 million years ago. Caused by the effects and side-effects of tremendous volcanoes, it radically altered the composition of both marine and terrestrial communities.
• In the time after this Permo-Triassic extinction, reptiles (and especially a branch that includes the ancestors of crocodilians and dinosaurs) diversified and became ecologically dominant in most medium- to large-sized niches.
• During the Triassic many of the distinctive lineages of the modern terrestrial world (including turtles, mammals, crocodile-like forms, lizard-like forms, etc.) appeared. Other groups that would be very important in the Mesozoic but would later disappear (such as pterosaurs and (in the seas) ichthyosaurs and plesiosaurs) evolved at this time.
• Dinosaurs were initially a minor component of these Triassic communities. Only the tall, long-necked sauropodomorphs were ecologically diverse during this time among the various dinosaur branches. However, a mass extinction event at the end of the Triassic (essentially the Permo-Triassic extinction in miniature) allowed for the dinosaurs to diversify as their competitors had vanished.
• During the Jurassic, dinosaurs diversified. Some grew to tremendous size; some evolved spectacular armor; some become the largest carnivorous land animals the world had seen by this point. Among smaller carnivorous dinosaurs, an insulating covering of feathers had evolved to cover the body (possibly from a more ancient form shared by all dinosaurs). Among the feathered dinosaurs were the ancestors of the birds.
• Other terrestrial groups such as pterosaurs, crocodile-ancestors, mammals, and insects continued to diversify into new habits.
• During the Jurassic and (especially) the Cretaceous, a major transformation of marine life occurred. Green-algae phytoplankton were displaced by red-algae phytoplankton (which continue to dominate modern marine ecosystems). A wide variety of new predators—advanced sharks and rays, teleost fish, predatory snails, crustaceans with powerful claws, specialized echinoids, etc.—appeared, and the sessile surface-dwelling suspension feeders that dominated the shallow marine communities since the Ordovician became far rarer. Instead, more mobile, swimming, or burrowing forms became more common.
• During the Cretaceous one group of land-plants evolved flowers and fruit and thus tied their reproduction very closely with animals. Although not immediately ecologically dominant, this type of plants would eventually come to be the major land plant group.
• The impact of a giant asteroid—coupled with other major on-going environmental changes—brought an end to the Mesozoic. Most large-bodied groups on land and sea, and many smaller bodied forms, disappeared. The only surviving dinosaurs were toothless birds.
• The beginning of the Cenozoic saw the establishment of mammals as the dominant group of large-bodied terrestrial vertebrates. Early on mammals colonized both the sea and the air as well.
• During its beginning the Cenozoic world was warm and wet, much like the Cretaceous. However, a number of changes of the position of the continents and the rise of mountain ranges caused the climates to cool and dry.
• As the world cooled and dried, great grasslands developed (first in South America, and later nearly all other continents).
• Various groups of animals adapted to the new grassland conditions. Herbivorous mammals became swift runners with deep-crowned teeth, often living in herds for protection. Mammalian predators became swifter as well, some becoming pack hunters.
• Other new plant communities evolved, and new animal communities which inhabited them. The rise of modern meadows (dominated by daisy-related plants and grasses) saw the diversification of mouse-and-rat type rodents, many frogs and toads, advanced snakes, songbirds, etc.
• A group of arboreal mammals with very big brains, complex social communities, and gripping hands—the primates—produced many forms. In Africa one branch of these evolved to live at mixed forest-grassland margins, and from this branch evolved some who became fully upright and moved out into the grasslands.
• This group of primates retained and advanced the ability to use stone tools that its forest-dwelling ancestors already had. Many branches evolved, and some developed even larger brains and more complex tools. It is from among these that the ancestors of modern humans and other close relatives evolved, and eventually spread out from Africa to other regions of the planet.
• About 2.6 million years ago a number of factors led to ice age conditions, where glaciers advanced and retreated. Various groups of animals evolved adaptations for these new cold climates.
• The early humans managed to colonize much of the planet; shortly after their arrival into new worlds, nearly all the large-bodied native species disappeared.
• At some point before the common ancestor of all modern humans spread across the planet, the ability to have very complex symbolic language evolved. This led to many, many technological and cultural diversifications which changed much faster than the biology of the humans themselves.
• In western Asia and northern Africa (and eventually in other regions), modern humans developed techniques to grow food under controlled circumstances, leading to true agriculture. (Other cultures are known to have independently evolved proto-agricultural techniques).
• This Neolithic revolution allowed for the development of more settled communities, specialization of individual skills within a community (including soldiers, metallurgists, potters, priests, rulers, and with the rise of writing, scribes).
• From this point we begin to get a written record, and so the historians can take up the story…

Things are moving along well in the lab this winter, and one of our long term projects that we hope to tackle soon is the removal of the huge field jacket of RMDRC 07-022 “Joyce”, a medium-sized crested duckbill from the Judith River Formation of central Montana. Joyce was discovered by rancher Larry Tuss on private land leased by TPI for fossil collecting, and is named after his lovely wife.

The dig was hot, and we were visited by film crews from Australian Broadcasting and NBC. The animal is moderately complete and partially articulated, however the tail was lost due to cretaceous erosion. Nothing like being 70 million years late to the party.

Currently the main jacket is being re-hydrated so that the matrix can be safely removed and the bones extracted from the middle of the prep lab. Photo above is the right lower jaw and part of the upper jaw. Any duckbill guys know if it’s distinctive to genus level?