Monday, November 19, 2018

Charismatic Kansan Megafauna

Eerie eye of a hungry mosasaur!
This is the third in a series of posts about my visit to the Kansas chalk (1)—the remains of the great Western Interior Seaway which covered a large swath of North America roughly 100 to 60 million years ago. I was most taken by the chalk itself—its planktonic composition, the conditions in which it formed (imagine Kansas underwater!), and the bizarre picturesque outcrops in the valley of the Smoky Hill River. However it’s not the chalk that most people get excited about, but rather what it contains—lots of well-preserved fossils of gigantic beasts now long gone.

This is not to say I had no interest in the chalk’s fossils. In fact, I was eager to see the creatures of the Seaway, and I devoted an entire day to the Sternberg Museum of Natural History in Hays. It was well worth the hundred-mile drive (each way).

But first a quick review. About 87 to 82 million years ago, Kansas lay in the middle of the Western Interior Seaway, far enough from shore that little terrestrial debris washed in. Instead, seafloor sediments were dominated by dead plankton, mainly the calcareous scales of coccolithophores, which rained down in abundance.
Red X marks Kansas (USGS).
Coccolithophores thrived in the Kansas sea. Their microscopic scales formed chalk beds 600 feet thick! (source).
Occasionally carcasses of bigger creatures fell to the seafloor and were entombed in the limy muck. With pressure from overlying sediments, the muck became chalk. Uplift, retreat of the sea, and finally erosion exposed the chalk and the remains of those long-dead animals—today’s fossils.
Collecting a Xiphactinus fossil (large fish) from the Kansas chalk, early 20th century (Fick Museum, Oakley).
Originally, a fossil was simply something “obtained by digging” (from L. fossilis). But in the 18th century, usage became restricted to preserved remains of living organisms (including impressions, and traces such as burrows and tracks). Fossils are common in the Smoky Hill Chalk, and often spectacular. Not surprisingly, when word got out that there was a treasure trove of novel fossils awaiting discovery in western Kansas, the big names in North American paleontology got really excited.

In 1870, Professor Othniel Marsh of Yale and his students rode the Union Pacific Railroad as far as North Platte, Nebraska. Joined by a military escort, they explored the fossil-rich country of western Nebraska before continuing across Wyoming to Salt Lake City and finally San Francisco. On the return trip, they made just a quick stop in Kansas, in the valley of the Smoky Hill River. But it was long enough for Marsh to make the discovery that sparked his passion for the Kansas chalk—a strange hollow bone, probably the finger of something that flew! Though it was the end of the day and fast getting dark, he carefully excavated the bone and precisely noted the location.

The next year, Marsh returned to the site and collected the wing bones of a giant pterosaur—far larger than any previously described, and the first found outside of Europe. After several years of taxonomic wrangling, it became Pteranodon (2), now one of the two state fossils of Kansas (3).
Marsh with his students, ready for adventure! (source)
A few years later, local farm boy and fossil enthusiast Charles H. Sternberg enrolled at Kansas State Agriculture College, where he heard some exciting news. Professor B.F. Mudge (also the state geologist) would lead a party of students to search the chalk for fossils for Professor Marsh! Though the expedition was full, Sternberg “made every effort within my power” to join. But he was turned down.

In despair, and desperate to collect fossils in the chalk, Sternberg wrote to another leading paleontologist, Professor Edward Drinker Cope of Philadelphia—who happened to be Marsh’s arch rival.
“I put my soul into the letter I wrote him, for this was my last chance. I told him of my love for science, and of my earnest longing to enter the chalk of western Kansas and make a collection of its wonderful fossils, no matter what it might cost me in discomfort and danger.”
Sternberg explained that he was too poor to finance a trip himself, and asked for $300 for a wagon, horses, camping gear, a cook and driver. He sent no recommendations “from well-known men” but did mention his earlier work collecting fossil leaves in central Kansas. Cope quickly replied, sending a draft for three hundred dollars and a note: “I like the style of your letter. Enclose draft. Go to work.”

What are the chances today that a preeminent scientist would send funding to some unknown local?! Those were different times, it’s true, but there’s another likely factor—Cope’s bitter rivalry with Marsh (4). Cope surely was eager to get his hands on fossils from the Kansas chalk. As it would turn out, that $300 was a wise investment.

Charles H. Sternberg spent four hard but happy and productive years collecting fossils for Cope, the beginning of a fossil-collecting dynasty that included Charles and his three sons—George F., Charles M. and Levi. The Sternberg family often named children after relatives, so the full story can be hard to follow. But for this post, we only need to know Charles H. and his oldest son, George F. The latter was named after his uncle, George M., an army surgeon stationed in Kansas (and later US Surgeon General) who convinced his father to move the family there to farm.
By age 17, Charles H. Sternberg (1850-1943) knew he would devote his life to fossil-collecting. His father thought it a poor choice (source).
George F. Sternberg (1883-1969) collected his first important fossil, a novel plesiosaur, at age nine. His contributions to Kansas paleontology were monumental (Fick Museum, Oakley).
After graduating from high school, George F. worked in the family fossil business full time, earning widespread respect for his collecting and research. Lack of a college education was never a problem until the Western Branch of the Kansas Normal School (today’s Fort Hays State University) discovered that without a college degree, Sternberg could not be hired as a professor. So he became museum curator, a position he held until 1962. After his death in 1969, the museum was renamed in his family’s honor.

George F. Sternberg (source).
At the Sternberg Museum, I paid a modest fee and entered the first floor of exhibits. I immediately spotted George F. Sternberg, who was carefully excavating a huge fish fossil! It was one of his most famous discoveries—the Fish-Within-A-Fish—a Xiphactinus that died not long after swallowing a Gillicus. It’s on display next to George.
At 14 feet in length, this is a rather average Xiphactinus.
George F.’s Fish-Within-A-Fish advertises the Lithic Bookstore and Gallery in Fruita, Colorado. 
Just across from Xiphactinus is a huge Dragon of the Sky—Pteranodon, the Kansas flight fossil (3) and logo of the Sternberg Museum. It was the fossilized finger bone of a Pteranodon that got Professor Othniel Marsh excited about the Kansas chalk. Marsh’s first description had some serious errors due to lack of body parts and careless packing—a Xiphactinus tooth got mixed in (source). Based on wing bones and the errant tooth, Marsh concluded this animal was similar to European toothed pterosaurs. But when skeletons were found with skulls, he had to revise his thinking. This pterosaur had a giant crest on its head and no teeth—a brand new kind! Marsh changed its name to Pteranodon (2).
Note the massive crest atop Pteranodon’s head and framed on the left (museum logo added).
The exhibits were so beautiful, as well as educational, that I spent a lot of time taking photos and notes.
Shark vertebrae.
GillicusXiphactinus’s last supper—also was a predatory fish.
Seymouria is much older than the chalk, but was too photogenic to ignore. An amphibian with reptilian features, it lived roughly 275 million years ago. This one is about two feet long.
Exhibits about local geological history and stratigraphy were a terrific help in understanding the context of Kansas chalk. I'm glad I visited the Museum early in my trip. Below are two formations from the stratigraphy exhibit—the beloved Niobrara Formation (because it includes the chalk) and the younger Pierre Shale, which is made of fine terrestrial sediments indicating the Seaway was in retreat.
The Sternberg is a natural history museum that includes much more than fossils from the Smoky Hill Chalk. But they were my focus, and they kept me busy for several hours. Not surprisingly, these are mainly marine animals—shellfish, sharks, fish (some huge!), giant turtles and other hulking creatures like the mosasaur, a giant reptilian marine predator (5).
Though big, reptilian and now extinct, mosasaurs (above and below) are not a dinosaurs. Why? … see Were Pterosaurs and Mosasaurs Dinosaurs? for a simplified explanation.
The most popular members of the Mesozoic megafauna are rarely found in the chalk—the dinosaurs. They were terrestrial, so were absent from the Seaway. A notable exception is Niobrarasaurus—notable enough that it has its own exhibit. It’s a puzzle: How did a terrestrial creature end up on the seafloor far from land? Perhaps it died on shore, and its bloated carcass washed out to sea where it floated for some time before finally sinking. This is the “Bloat & Float” hypothesis.
A reptilian tank with armored plates.
Niobrarasaurus was named for the Niobrara Formation, of which the Smoky Hill Chalk is a member. The creature was “built like a tank” and covered in armored plates, which may have helped maintain the bloat. This fossil was excavated from the chalk in 1930, and shipped off to the University of Missouri in Columbus. Seventy-two years later, Niobrarasaurus was repatriated, and is now on display at the Sternberg Museum.

Not Cretaceous, but I couldn’t pass it by!
After several hours on the first and second floors, including an irresistible detour to see all 22 of our rattler species live! (behind glass), I checked the gallery guide and saw there was a third floor, featuring an Upland Diorama. Memories surfaced of the simple small-scale less-than-realistic dioramas in the natural history museums we visited as kids. I have fond memories of those visits, so I started up the stairs. But before I got even halfway, it became obvious …
Oh my! Hadrosaur ahead!!
… my expectations were wrong! This is a life-size realistic total-immersion diorama. Pterosaurs flew overhead, specifically Pteranodon sternbergii, named for George F., who collected the first specimen in 1966. Life-size sculpted creatures mingled with more of their kind in the panoramas on the walls behind.
These scenes would have been in Colorado, on the west shore of the Western Interior Seaway. And there on the beach I spotted the dead bloated Niobrarasaurus, not yet washed out to sea.
From the beach, I descended through the Schmidt Exhibit, walking away from shore along the floor of the Seaway. First there were sandy beach deposits, then finer sediments—silt and clay—in deeper water. Far from shore, I reached the wonderful limy muck—planktonic debris overlying limestone and chalk (sediment labels added).
Finally, the walkway rounded a corner and I floated off through the waters of the Western Interior Seaway  face-to-face with its charismatic megafauna!
Yikes! Xiphactinus!!

Notes

(1) Other posts in this series are To Kansas to See the Chalk and A Ghost Rock Speaks.

(2) Some paleontologists now place Pteranodon sternbergii in the genus Geosternbergia (source).

(3) Pteranodon is the Kansas flight fossil. Tylosaurus, a mosasaur, is the Kansas marine fossil. Both are from the Smoky Hill Chalk. Nothing wrong with having two state fossils, especially given Kansas’s impressive fossil heritage! More here.

(4) The Marsh-Cope rivalry was bitter and brutal. Both “used underhanded methods to try to outdo the other in the field, resorting to bribery, theft, and the destruction of bones. Each scientist also sought to ruin his rival's reputation and cut off his funding, using attacks in scientific publications.” (from Bone Wars).

(5) The photo at top of post is the mosasaur Tylosaurus, the Kansas marine fossil (full skull below). It’s on display at the Fick Museum in Oakley, which is much smaller than the Sternberg, but fascinating and worth a visit.

Sources

Liggett, GA. 2001. Dinosaurs to dung beetles: expeditions through time. Hays, KS: Sternberg Museum of Natural History.

Sternberg, CH. 1909, reprinted 1990. The life of a fossil hunter. Indiana University Press. Recommended reading!

Sternberg Museum of Natural History. Gallery Guide. Available here.

2 comments:

  1. That's a mouthful (sorry, I couldn't resist). It's fun to try to imagine the excitement of those expeditions--especially being a young person starting out. Yes, the displays are beautiful...and informative! Thanks for sharing!

    ReplyDelete
    Replies
    1. ha ha, I like it ... thanks, Beth! Anytime I find an historical expeditions associated with these stories, I get excited--vicariously participation.

      Delete