Seth Finnegan, Professor

Open (1) The evolution of mollusk shell ornamentation as a defense against predation

Open. Apprentices needed for the fall semester. Please do NOT contact faculty before September 11th (the start of the 4th week of classes)! Enter your application on the web beginning August 16th. The deadline to apply is Tuesday, August 29th at 8 AM.

The Mesozoic era (252 – 66 million years ago) saw the rise of various marine predators such as marine reptiles, shell-breaking crustaceans, drilling gastropods, and teleost fishes. As a result, predation pressures are suggested to have increased during this ‘Mesozoic marine revolution’, especially towards the end of the Mesozoic. The degree to which the behavioral and morphological evolution of prey species was driven by this trend has been debated for decades. If escalation, or predator-driven evolution, is a valid hypothesis, there should be a correlation between the diversity and/or abundance of shell breaking and crushing predators and the degree of defensive ornamentation and armoring of prey species.

The focus in this research will be on marine gastropods and bivalves from the Cretaceous period (145 – 66 million years ago). These invertebrates were abundant during the Cretaceous and were commonly preyed upon by shell-breaking and drilling predators as recorded by attack and repair scars . Experimental data show that their shell ornamentation or armor (spines, ribs, etc.) can help to deter predation and lower successful predation rates.


The student will assemble a literature-based database on the ornamentation of epifaunal bivalve and gastropod mollusks to determine whether or not there is a trend towards increased ornamentation throughout the Cretaceous in these clades. Subsequently, the most likely time of origin of ornamentation in relevant lineages will be evaluated to assess whether or not ornamental traits may have evolved as a result of increased predation pressures. This research may lead to an abstract to be presented at a conference or symposium.

Day-to-day supervisor for this project: Adiel Klompmaker, Post-Doc

Qualifications: A disciplined and self-directed student with an interest in marine ecology and/or paleontology. Some geological background is a plus, but not required. Familiarity with spreadsheet.software such as Excel is a plus.

Weekly Hours: to be negotiated

Related website: http://finneganlab.org

Open (2) Comparative Life History and Physiology of Pleistocene-Recent Pacific Coast Bivalves

Open. Apprentices needed for the fall semester. Please do NOT contact faculty before September 11th (the start of the 4th week of classes)! Enter your application on the web beginning August 16th. The deadline to apply is Tuesday, August 29th at 8 AM.

Rapid climate changes during the Pleistocene (2.6 million years ago to 12,000 years ago) caused major range shifts among northeastern Pacific coastal invertebrates. These range shifts are documented by an excellent fossil record spanning from Baja California into Canada. This record demonstrates that species with non-overlapping modern ranges co-occurred during the Pleistocene, raising questions about the processes controlling range shifts within and among species

Bivalves (clams) are one of the major components of the Pleistocene marine record, and the UC Museum of Paleontology (UCMP) has extensive fossil bivalve collections. Because they grow by accretion, the shells of clams record a great deal of information about both the environment in which they lived and the life history of the individual (growth rate, season of maximum growth, changes in diet, age at mortality, season of mortality, etc.).



This project will use the UCMP collections to examine variation in these aspects of individual life history and physiology across a range of environmental conditions using both both recent and fossil shells of selected bivalve species. The student will be supervised by an IB graduate student and will assist in choosing collections and in making detailed measurements of the shape, size, and growth rings of selected specimens. The student will also assist in sectioning some specimens and using a very fine drill to sample the shell at different points in its history and analyze changes in shell chemistry that can indicate seasonal and ontogenetic variation in diet and metabolism.

Related projects may be developed if interest arises.

Qualifications: Qualifications: Looking for a disciplined and self-directed student with a strong interest in marine ecology and in Earth history. Some geological background a plus but not required. Familiarity with stable isotope ecology a plus.

Weekly Hours: to be negotiated

Related website: http://finneganlab.org

Open (3) Effects of the uplift of the Isthmus of Panama on the ecology, evolution, and extinction of Caribbean bivalves

Open. Apprentices needed for the fall semester. Please do NOT contact faculty before September 11th (the start of the 4th week of classes)! Enter your application on the web beginning August 16th. The deadline to apply is Tuesday, August 29th at 8 AM.

The rise of the Isthmus of Panama ~3 million years ago was arguably the most important biotic and oceanographic event of the past 60 million years. By connecting North and South America, the rise of the Isthmus caused the Great American interchange of terrestrial plant and animal species. In the oceans, the rise of the Isthmus had the opposite effect: the Caribbean Sea was cut off from the tropical eastern Pacific Ocean, and formerly continuous marine populations were severed. Prior to the rise of the Isthmus of Panama, the environment of the proto-Caribbean resembled that of the modern-day tropical eastern Pacific, with upwelling of cold, nutrient-rich bottom waters causing strong interannual and seasonal variations in temperature and planktonic productivity. The modern Caribbean does not experience upwelling, and hence temperatures are nearly constant and planktonic productivity very low. Hence, Caribbean species have evolved (or gone extinct) in a radically changed environment for the past 3 million years.

This project will examine how the rise of the Isthmus of Panama affected the evolution and ecology of one major group by looking at the rich fossil record of bivalve mollusks (clams). Bivalves are abundant and very well preserved in marine sedimentary rocks from Central America that span the interval during which uplift of the isthmus occurred. The student will examine fossil collections to characterize the trophic structure, size-frequency distribution, and (in some cases) the age structure of bivalve communities from before, during, and after the uplift of the Isthmus. The student will also examine species stratigraphic ranges (oldest and youngest fossil occurrences) and ecological characteristics to determine how the species that went extinct following uplift of the isthmus differed from those that survived.



Weekly Hours: to be negotiated

Related website: http://finneganlab.org

Open (4) Environmental control on the biodiversity and body size of crustaceans

Open. Apprentices needed for the fall semester. Please do NOT contact faculty before September 11th (the start of the 4th week of classes)! Enter your application on the web beginning August 16th. The deadline to apply is Tuesday, August 29th at 8 AM.

Increasing temperatures due to climate change today allow for the poleward migration of species on land and in the ocean, potentially leading to shifts in biodiversity and body size. However, habitat type also affects body size and diversity, influencing patterns due to temperature alone. The long-term effects of climate change can only be tested directly using the fossil record. Using Cenozoic fossil decapod crustaceans, a diverse and ecologically important group inhabiting all marine habitats, the goal of this project is to test a variety of exciting hypotheses not tested previously: (1) diversity increases, while body size decreases towards the tropics; (2) the late Cenozoic cooling led changes in diversity and body size along the coasts of the Americas; and (3) reef environments harbor smaller crustaceans than do other environments.

The student will assemble and analyze a dataset on the crustacean biodiversity and body size to test one or several of these hypotheses. There may be opportunities to augment the dataset with data from specimens deposited in the UCMP (University of California Museum of Paleontology).

Day-to-day supervisor for this project: Adiel Klompmaker, Post-Doc

Qualifications: A disciplined and self-directed student with an interest in marine ecology and/or paleontology. Some background in biology or geology is a plus, but not required. Familiarity with spreadsheet software such as Excel is a plus.

Weekly Hours: to be negotiated

Related website: http://finneganlab.org