5 available master thesis:
Bone microstructure of ichthyosaurs and whales
Background:
Vertebrate skeletons have many functions, and their structure is influenced by ontogeny, locomotion and the environment. By looking at the inner microstructure of the bones of fossil ichthyosaurs, we can understand more about how they grew, swam and reproduced.
Several master thesis projects are available to study inner bone microstructure of limb and girdle elements of extinct ichthyosaurs and modern whales. This is part of the work in the research project ECHO, where we study the convergent evolution of these two groups. We will determine the timing and order of evolutionary innovations that led to the thunniform body shape, and correlate temporal events with changes to inner bone microstructure.
Research aims:
- Map the inner microstructure of ichthyosaur and/ or whale limb and girdle elements (such as porosity, tissue types, growth signatures).
- Calculate its relation to locomotion pattern and buoyancy.
- Detect the amount of convergence.
Method:
Microstructure can be studied in many ways; using classical thin sections, CT scanning or acetate peels, and we aim to combine several methods. Through this project you will learn about the inside of the vertebrate skeleton, adaptations to marine life and convergent evolution.
The vertebral column in marine tetrapods
Background:
The vertebral column is the single most characteristic trait of all vertebrates. Still, there are many unanswered questions with regard to its growth and evolution, especially for secondarily marine vertebrates. Ichthyosaurs were Mesozoic marine reptiles that evolved a body shape very much like modern toothed whales, and had a series of disk-shaped vertebrae. This project will describe the shape and proportions of fossil vertebrae of Late Jurassic ichthyosaurs from Svalbard. It will also map the relation between outer and inner bone characteristics. This master project is part of the research project ECHO, where we study the convergent evolution of whales and ichthyosaurs.
Research aims:
- Scientific description and comparison of six ichthyosaur vertebral columns.
- Map the extent of regionalization in ophthalmosaurid ichthyosaurs.
- How does the outer morphology of the vertebrae match inner bone microstructure?
- Do ichthyosaurs and whales show the same adaptations?
Method:
The six vertebral columns are prepared, and will be photographed, measured and CT scanned, and scientifically described. Through this project you will work on comparative anatomy of the vertebral column and its relation to evolution and locomotion in marine tetrapods.
Late Jurassic ichthyosaurs from Spitsbergen
Background:
Ichthyosaurs were Mesozoic marine reptiles that evolved a body shape very much like modern toothed whales. At Svalbard, 26 ichthyosaur specimens from the Jurassic age have been excavated, and some of them are still not scientifically understood. Three ichthyosaur specimens are in need of being documented and described. Two of these need preparation, which can be part of the master project. This master is part of the research project ECHO.
Research aims:
- Scientific description of the undocumented ichthyosaurs.
- What species of ichthyosaurs are these specimens?
- How are they phylogenetically related to other ichthyosaur taxa?
Method:
Through this project, you can learn fossil vertebrate preparation, in addition to solving the puzzle of what ichthyosaurs these are. You will use skeletal data and comparison to other taxa, focusing on the comparative anatomy of vertebrate evolution and adaptations to marine life. It can be possible to combine physical preparation with CT data.
Body proportions in streamlined marine predators
Background:
The most obvious convergence between whales and ichthyosaurs indicative of coinciding ecological roles is their body shape. Also shared by several fish species, this hydrodynamic profile has been optimized to reduce drag, with a streamlined length roughly 4.5 times that of its max. diameter, the “thunniform” body shape facilitates fast, sustained swimming to catch prey. However, the actual body proportions and scaling between different skeletal elements is unknown for many taxa. This project will map the size of different body parts (skull, vertebral column, fins) in ichthyosaurs and toothed whales, enabling a comparison between the two. This master is part of the research project ECHO, where we study the convergent evolution of these two groups.
Research aims:
- Do modern toothed whales and dolphin-looking ichthyosaurs share the same skeletal proportions?
- Are fins and tails used in the same way for speed and manoeuvring?
- How does skull size evolve?
Method:
The data for this project will be collected from museum specimens of fossil ichthyosaurs and modern toothed whales. You will collect size and shape data from a number of selected groups, and compare statistically.
Body size in a fossil assemblage of marine reptiles
Background:
Body size is one of the most apparent and important features in organismal biology, influencing many aspects of physiology, ecology and life history. Ichthyosaurs were Mesozoic marine reptiles that evolved a body shape very much like modern toothed whales. At Svalbard, 26 ichthyosaur specimens from the Jurassic age have been excavated, from a time span of approx. 12 million years. This project will study the body size within the assemblage.
Research aims:
- What is the range of body sizes in this assemblage?
- What controls the body size of these ichthyosaurs; ontogeny, taphonomy or ecology?
- How does the body size composition compare to other assemblages worldwide?
Method:
This project will use skeletal measurement data for the ichthyosaurs from the Slottsm?ya Member. It will be necessary to combine measurements for different body parts, and compare these in a statistically robust way. This master is part of the research project ECHO.