Rebecca Mink

IDENTIFICATION AND MORPHOMETRIC VARIATION WITHIN A POPULATION OF EDMONTOSAURUS (ORNITHISCHIA: HADROSAURINAE)

I am grateful to have the opportunity to work with a collection of Edmontosaurus (duck-billed dinosaur) bones, which is curated at Concordia College, Moorhead, MN. The duckbills are a group of dinosaurs that lived during the Late Cretaceous, towards the end of the time of the dinosaurs. They are specialized herbivores for having a “battery” of teeth, used to grind massive amounts of food. Edmontosaurus, along with Triceratops, were the Cretaceous cows, i.e., eating machines. The Edmontosaurus bones come

from a fossil locality in South Daktoa (see inset picture) that represents a Cretaceous riverine deposit that is currently in the hillside. Apparently, the Edmontosaurus bones were deposited during a single catastrophic event because all sizes of individuals are represented. My research objectives for the Edmontosaurus fossils include 1) their taxonomy, as well as 2) describing the amount of variation found within the population.

In truth, very little is known about the genus Edmontosaurus. Currently, it is thought that the genus is comprised of three species: E. annectens, E. saskatchewanensis, and E. regalis. The holotype material for E. saskatchewanensis and E. regalis is curated at the Canadian Museum of Nature and are picutred below. More taxonomic work needs to be done to differentiate the three species as most studies focus on the elaborately crested Lambeosaurines, rather than the flat-headed Hadrosaurines. An additional but interesting tier of difficulty is the Edmontosaurus bone bed is comprised of random, disarticulated hadrosaur bones (i.e., equals a mess of prehistoric proportions). The animals are fascinating however, and their remains are in beautiful condition.

Will Bleier
Department of Biological Sciences, North Dakota State University, Fargo, ND 58105-5517
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Ron Nellermoe
Department of Biology, Concordia College, Moorhead, MN 56562
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Rhonda Magel (Graduate School Representative)
Department of Statistics, North Dakota State University, Fargo, ND 58105-5575
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General Research Interests and Background

Dinosaurs have been an interest of mine since I was six, when I caught a chronic case of Dinosauritis. From that time, anything large and reptilian has fascinated me (this includes dragons, which if you’re around me for a while, you’ll quickly find out!). While I love drawing and painting, I don’t have nearly enough time to do so, but I make up for this by restoring fossils. When I was young, it never occurred to me that artwork (2D and 3D) goes hand in hand with my current interests in anatomy and biology as technical restorations and sculptures facilitate my understanding of functionality, comparative anatomy, and osteological variation.

MORPHOMETRIC AND SURVIVABILITY EXPERIMENTS ON RANUNCULUS (BUTTERCUP) ACHENES RELATED TO THEIR OCCURRENCE AS FOSSILS IN THE MEYER DESERT FORMATION, SIRIUS GROUP, ANTARCTICA
Fossil Ranunculus achenes are abundant in the Neogene Meyer Desert Formation (Sirius Group), and a morphometric study of fossil achenes from that area of Antarctica showed a significant linear relationship. On the basis of moderate to high r² values (0.639 and 0.745) for plots of area against short and long axes, respectively, Ashworth and Cantrill (2004) suggested that the achenes were from a single species of Ranunculus. It was surmised that morphometric variation of fossil Ranunculus achenes was to be attributed to the position of the achenes on the flower head, rather than numerous species, and that additional variation was the result of wear within the depositional environment. In order to test these hypotheses, we needed to test the durability of modern Ranunculus achenes, as well as look at the variation found within one plant. For the durability test, we wanted to simulate a similar environment to that experienced by the fossil achenes, and thus took sediment directly from the Antarctic samples for use in the abrasive treatments.

TECHNICAL ILLUSTRATIONS
Artwork has been a part of my life even longer than dinosaurs. Nothing makes me happier than combining the two together. The link is to a small website that shows a sampling of some of my more technical fossil illustrations as well as my more informal portraits and wildlife paintings: frostdrake.deviantart.com.

Edmontosaurus Parietal	Departmental T-Shirt 2005

Curriculum Vitae (abbreviated)

PRESENTATIONS

Mink, R., and Ashworth, A. 2005. Morphometric and survivability experiments on Ranunculus (buttercup) achenes related to their occurrence as fossils in the Meyer Desert Formation, Sirius Group, Antarctica. Geological Society of America North-Central Annual Meeting, Minneapolis, MN. (Poster).

Mink, R. 2005. Variation in a Population of Edmontosaurus from Corson, Co, SD. Geological Symposium, North Dakota State University, Fargo, April. (Oral).

Mink, R., and Nellermoe, R. 2004. Vertical Quadrant Mapping of an Edmontosaurus Bone Bed, Corson, Co, South Dakota. Concordia Biological Symposium, Moorhead, MN. (Oral).

Gould (Mink), R., Larson, R, and Nellermoe, R. 2003. An allometric study comparing metatarsal II's in Edmontosaurus from a low-diversity hadrosaur bone bed in Corson Co. S.D. Society of Vertebrate Paleontology 63^rd Annual Meeting. St. Paul, Minnesota, October 15-18. Journal of Vertebrate Paleontology 23(supplement to 3):56A. (Poster).

Larson, R, Nellermoe, R., and Gould (Mink) R. 2003. A study of theropod teeth from a low-species-density hadrosaur bone bed in the lower Hell Creek Formation in Corson Co. S.D. Society of Vertebrate Paleontology 63^rd Annual Meeting. St. Paul, Minnesota, October 15-18. Journal of Vertebrate Paleontology 23(supplement to 3):70A. (Poster).

Mink, R. 2002. Discovering Dinosaurs. Lake Agassiz Regional Libraries. Moorhead, MN. (Oral).

TEACHING EXPERIENCE
2007 – Comparative Chordate Morphology Lab Teaching Assistant, Zoology 280, Department of Biological Sciences, North Dakota State University, dates of 1/9 to 5/12, three sections of a one credit, semester length course.

2006 – Comparative Chordate Morphology Instructor, Zoology 280, Department of Biological Sciences, North Dakota State University, dates of 8/22 to 12/15, a four credit, semester length course.

2006 – Comparative Chordate Morphology Lab Teaching Assistant, Zoology 280, Department of Biological Sciences, North Dakota State University, dates of 1/9 to 5/12, three sections of a one credit, semester length course.

2005 – Human Anatomy and Physiology Lab Teaching Assistant, Biology 220, Department of Biological Sciences, North Dakota State University, dates of 8/22 to 12/15, three sections of a one credit, semester length course.

2005 – Comparative Chordate Morphology Lab Teaching Assistant, Zoology 280, Department of Biological Sciences, North Dakota State University, dates of 1/9 to 5/12, three sections of a one credit, semester length course.

2004 – Human Anatomy and Physiology Lab Teaching Assistant, Biology 220, Department of Biological Sciences, North Dakota State University, dates of 8/22 to 12/15, three sections of a one credit, semester length course.

Becky Mink

Masters Project

General Research Interests and Background

Curriculum Vitae (abbreviated)

Edmontosaurus saskatchewanensis CMN 8509	Edmontosaurus regalis CMN 2288