Funded PhD opportunities

Why are there no fossil cacti? The taphonomy of a diverse clade of angiosperm xerophytes

  • Application end date: 11th February 2018
  • Funding Availability: Funded PhD project (EU/UK students only)
  • Department: School of Earth and Environmental Sciences
  • PhD Supervisor: Professor David M. Martill, Dr Nicholas Minter and Dr Anthony Butcher

Project code: SEES4040218

Project description

The aims of this study are to determine the resistance of the various components of a cactus plant to transport and microbial decay in order to identify those components with the potential to enter the fossil record, and what they might look like in that record. The field based study will allow the results of the actualistic study to be tested in real environments, including arid rocky and sandy desert, and ephemeral fluvial settings, all the way to a marine sedimentary basins (Wagner Basin, Baja California) over a transport distance of approximately 80 km.

The main objective of the two combined studies is to understand why Cactacea should be absent from the fossil record, or if palaeontologists are failing to recognise their remains. Perhaps taphonomic artefacts caused by decay and transport hinder their recognition.

This project will examine the taphonomy of Cactacea in a two-pronged approach. An actualistic laboratory based study will examine the decay and resistance to decay processes of cactus micro components (seeds, pollen, phytoliths, glochid components, cuticular structures) and their macrophyte remains (woody tissues, fruits) to determine decay pathways in a variety of xeric conditions. A field based study will examine the residual components of cactus phytodebris in xeric environments of the Sonora Desert on the Arizona - Mexico border at Organ-Pipe Cactus National monument. The decay study will monitor the decay and induction of taphonomic artefacts over time series experiments, using light microscopy and scanning electron (SEM) microscopy to observe morphological transformations.

Field studies will examine in-situ decomposition of a range of taxa (including Mammillaria, Echinocactus, Carnegia, Opuntia, Cylindropuntia), and transport distances along two fluvial systems that debouch into Baja California’s Wagner Basin. This study will involve collection of dead phytodebris and photography coupled with detailed location data. Training will include field data collection techniques, scanning electron microscopy experimental design, as well as a wide variety of laboratory techniques and statistical methods.

Supervisor profiles

Professor David M. Martill

Dr Nicholas Minter

Dr Anthony Butcher

Admissions criteria

You’ll need a good first degree from an internationally recognised university (depending upon chosen course, minimum second class or equivalent) or a Master’s degree in an appropriate subject. Exceptionally, equivalent professional experience and/or qualifications will be considered. English language proficiency at a minimum of IELTS band 6.5 with no component score below 6.0.  


Informal enquiries are encouraged and can be made to Prof David Martill at (02392 842256) or Dr Nicholas Minter at (02392 842288).

For administrative and admissions enquiries please contact

How to Apply

You can apply online at  You are required to create an account which gives you the flexibility to save the form, log out and return to it at any time convenient to you.

A link to the online application form and comprehensive guidance notes can be found at

When applying, please quote project code: SEES4040218.

Interview date: TBC

Start date: 1st October 2018.

Funding notes

The fully-funded, full-time three-year studentship provides a stipend that is in line with that offered by Research Councils UK of £14,553 per annum.

The above applies for Home/EU students only. 

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