Our Discovery of the Western Interior Sea
When Lewis and Clark set out in 1804 on their westward trek to explore the Louisiana Purchase, they had no idea they would also be crossing the expanse of an ancient ocean that once covered the middle of North America. It was early in the trip when they found the only fossil from the collections made by the expedition that survives today Chapter 5 . Along the Missouri River, near the northwest corner of what is now Iowa, they came across a fossil that Meri-wether Lewis described in a note that...
Stratigraphy
One of the important issues that will surface again and again in this book is the lack of stratigraphic information on the occurrence of most of the fossils that have been collected from the Smoky Hill Chalk. In this usage, stratigraphic occurrence refers to what approximate chronological level the fossil was found within the 2 00-m 600-ft. chalk unit. As noted earlier, this chalk was deposited in the Western Interior Sea over a period of about five million years. Fossils found near the bottom...
Table 1
Biostratigraphy of the Smoky Hill Chalk adapted from Hattin, 1982 Stewart, 1990 Everhart, 2001 . Time MYA Millions of Years Ago and boundaries as indicated by Hattin's 1982 marker units MU are approximate. The Smoky Hill Chalk Member of the Niobrara Chalk was deposited between 87 and 82 million years ago. Note that the Late Coniacian is unequally divided into two zones a lower zone P. pemiciosa from the base of the chalk to about MU 5 and a brief
Table
Biostratigraphy of the Smoky Hill Chalk adapted from Hattin, 1982 Stewart, 1990 Everhart, 2001 . Time MYA Millions of Years Ago and boundaries as indicated by Hattin's 1982 marker units MU are approximate. The Smoky Hill Chalk Member of the Niobrara Chalk was deposited between 87 and 82 million years ago. Note that the Late Coniacian is unequally divided into two zones a lower zone P. pemiciosa from the base of the chalk to about MU 5 and a brief
Other Times Other Sharks
This book is generally focused on a small geologically speaking , five-million-year window of time during the Late Cretaceous when the Smoky Hill Chalk was deposited on the bottom of the Western Interior Sea. The fauna from that interval 8 7-8 2 mya is the most widely collected and the most thoroughly studied of any period from the Cretaceous of Kansas. The chalk is accessible in many localities, preservation is excellent and the chalk matrix is relatively easy to remove. It is also my favorite...
A Brief History of Fossil Fish Collecting in Kansas
Though not from Kansas, the first known fossil fish from the Niobrara Chalk was collected by the Lewis and Clark expedition in August of 1804 from the bank of the Missouri River in what is now Harrison County, Iowa. The fish jaw ANSP 55 16 is currently in the collection of the Academy of Natural Sciences of Philadelphia and is the only fossil specimen surviving from that expedition Spamer et al., 2000 . The history of this fossil is somewhat confused, however, because it was originally...
Fishes Large and Small
The big Xiphactinus swam effortlessly through the clear, warm waters of the Western Interior Sea in a solitary, never-ending search for its next meal. Ten years old and nearly four meters long, it had not yet reached full size, but it was already larger than any of the other species of fish in this ocean except the giant ginsu sharks. Although still wary of the occasional prowling shark, the X-fish's only other major competitor for the larger fish that it preyed upon were the large marine...
Sharks Sharp Teeth and Shell Crushers
The young adult mosasaur struggled wearily as it swam slowly just below the calm surface of the warm, shallow sea. It was the peak of the mosasaur breeding season. A chance encounter earlier that day with an enraged and much larger bull mosasaur had left his left front flipper crippled and useless. The six-meter marine reptile kept rolling over on its left side because the damaged flipper no longer provided the necessary steerage to keep him upright. Surfacing to breathe was difficult and his...
Xiphactinus Ichthyodectes and Gillicus
The family Ichthyodectidae is represented by three species in the Western Interior Sea. Most of the history of the discovery of Xiphactinus Portheus has already been discussed in the preceding paragraphs. The remains of Xiphactinus audax Leidy, Ichthyo-dectes ctenodon Cope, and Gillicus arcuatus Cope are found commonly as fossils in the Smoky Hill Chalk. Bardack 1 965 recognized four species of Xiphactinus and two species each of Ichthyodectes and Gillicus worldwide. Xiphactinus is the largest...
Ptychodus
The domed, shell-crushing teeth of ptychodontid sharks such as Ptychodus mortoni and P. anonymus are occasionally found one at a time like the teeth of other sharks. Sometimes, however, they occur in large numbers where they have eroded out on the surface of the chalk, or even as articulated jaw plates from a single individual Fig. 4.7 . These unusual sharks became extinct by the early Santonian in Kansas, and their teeth are only found in the lower one-third of the chalk. Due to a lack of...
Kansas during the Cretaceous A Timeline
For the most part, this book will discuss discoveries regarding the natural history of the Western Interior Sea during the deposition of the Smoky Hill Chalk during a period roughly between 87 and 82 million years ago mya . However, in order to better understand that time interval, it is useful to look at the Kansas oceans during that portion of the Cretaceous for which we have a geological record in the state. The Mesozoic Age of Reptiles is divided into three major periods the Triassic, the...
Coprolites
Coprolite is a scientific term for the fossilized excrement, feces, or droppings of ancient animals. It was coined by Dr. William Buckland 1829 . Coprolites are trace fossils, rather than body fossils bones, teeth, etc. . Hawkins 1834, pis. 27-28 illustrated several coprolites in his book on ichthyosaurs and plesiosaurs from the Jurassic of England. In the Smoky Hill Chalk, the coprolites that we find are probably from sharks, bony fish, and marine reptiles. This fossilized waste can often tell...
Laminospondylus Transversus
Classification of bony fishes of the Western Interior Sea Adapted from Subclass Actinopterygii Klein 1885 Incertae sedis Aethocephalichthys hyainarhinos Fielitz, et al., 1999 Infraclass Holostei Order Semionotiformes Suborder Lepisostoidei Family Lepisosteidae Lepisosteus Wiley and Stewart, 1977 Order Pycnodontiformes Family Pycnodontidae Micropycnodon kansasensis Hibbard and Graffham, 1945 Order Amiiformes Suborder Amioidei Genus Protosphyraena Leidy 1857 Protosphyraena pemiciosa Cope, 1874...
Sharks in the Late Cretaceous Western Interior Sea
Although it is about as far from an ocean as you can get, Kansas is a great, if unrecognized, place to find shark teeth. The first vertebrate remains reported in the state were two shark teeth and a dorsal fin spine from three different species of shark from the Carboniferous of Kansas Leidy, 1 859 . As settlements and the railroads moved further west, the first remains of Late Cretaceous sharks were recovered. LeConte 1 868, p. 8 reported the teeth and vertebrae of a species of shark belonging...
Invertebrates Plants and Trace Fossils
Little of the bright sunlight above ever reached the bottom of the Western Interior Sea. However, the steady rain of organic detritus from the plankton and other organisms in the water column supported an unusual abundance of life on the soft, muddy sea floor. Huge, flat clams called inoceramids literally covered the bottom, nearly edge to edge in many places, and if the scene had been visible to the eyes of a human visitor, it would have stretched outward in all directions for mile after...
Remains of Logs and Tree Limbs
Mudge 1877, pp. 283-284 was among the first to note the presence of an occasional fragment of fossilized wood. . . . This wood was, in a few instances, bored before fossilization by some small animal. This might have been done by the larva of an insect a 'borer' when the tree was living, or later by a teredo sic when the trunk floated in water. In either case it shows that the Cretaceous vegetation was subject to the same enemies as that of the present period. Some of this wood was in charred...
Protosphyraena
One fairly common genus in the Smoky Hill Chalk that was noticeably missing from Cope's 1872 list was Protosphyraena, a primitive Late Cretaceous swordfish that is well represented in the fossil record from as far away as Europe and Japan. A fragment of the pectoral fin was first figured and described from the English chalk by Mantell 1822 , and Leidy 1857 authored the name Protosphyraena ferox for the English specimens. Leidy 1865, pi. XX, figs. 7-9 also illustrated a Protosphyraena tooth from...
Contents
1 Introduction An Ocean in Kansas 1 Our Discovery of the Western Interior Sea 14 3 Invertebrates, Plants, and Trace Fossils 28 4 Sharks Sharp Teeth and Shell Crushers 46 5 Fishes, Large and Small 70 6 Turtles Leatherback Giants 102 7 Where the Elasmosaurs Roamed 120 8 Pliosaurs and Polycotylids 142 10 Pteranodons Rulers of the Air 188 Although I am almost a native Kansan and proud of my state, I have to admit that the drive across Kansas on Interstate 70 is not a major scenic experience if you...
Martinichthys Plethodidae
Another species named by Cope 1877b , Erisichthe ziphioides iA IN11 2 13 1 , was eventually determined to be a complete ' new and unrelated genus, Martinichthys, which was described by Mc-Clung in 1926. The type specimen consisted of a single bone or possibly a pair of bones that were fused forming a blunt rostrum that Cope ibid, p. 822 described as the muzzle of an old individual, which has lost a good deal of its apex by attrition. Hay 1 9 0 3, p. 2 2 believed it was simply a species having a...
Enchodus and Cimolichthys
Fish remains attributable to the genus Enchodus Agassiz 183 5 have been found worldwide and the genus apparently survives for a time past the Cretaceous Tertiary extinction event. Enchodus has been erroneously referred to as the Sabre-Toothed Herring because of the oversized teeth located on the palatines of the skull and the ends of the lower jaw. The genus is not related to herrings but instead is placed in the same order as modern salmon. Enchodus is represented in the Smoky Hill Chalk by at...
Pachyrhizodus
Xiphactinus has already been mentioned as the largest of the bony fish in the Western Interior Sea. However, the skull of a large specimen of Pachyrhizodus caninus FHSM VP-2189 at the Sternberg Museum is certainly as large as any Xiphactinus skull that I have seen. It is 56 cm 22 in. long and has teeth 4 cm long. The entire fish, however, would have been proportionally shorter than a Xiphactinus with the same sized head. Still, it would have been an impressive fish. Pachyrhizodus caninus Cope 1...