Personal Favourites
I've added a full list of publications lower down, but wanted to give these a bit more prominence: they're the ones I'm most proud of and particularly enjoyed working on (and some of them contain methods that I hope people will start using).
Brocklehurst, N., Kammerer C.F., Benson, R.B.J. 2020. The Origin of Tetrapod Herbivory: Effects on Local Plant Diversity. Proceedings of the Royal Society B (287): 20200124
- A look at how the origin of herbivory affected plant evolution in the Paleozoic. In the present day, herbivores can both enhance and also constrain plant diversity depending on how selective they are; more selective herbivores increase the predation pressure on more plants and reduce diversity, while more generalist herbivores prevent weed-like plants from dominating and give others a chance. The radiation of herbivores at the end of the Carboniferous is found to permanently constrain plant diversity. In particular, the plant diversity crash coincides with the radiation of small herbivores, which tend to be more selective.
Brocklehurst, N. 2019. Therocephalians break the hypercarnviore ratchet. Proceedings of the Royal Society B (286): 20190590
- An idea I'd had in my head for a while (I suggested it as a potential PhD project many moons ago, but switched to diversity) was to compare evolution of mammal carnivores to their therapsid relatives from the Permian and Triassic. Mammal carnivores seem to be very inflexible in their evolution; once they adopt a hypercarnivore specialisation, they stick to it, becoming ever more specialised and larger until extinction. However, therocephalians (a therapsid lineage) show a very different pattern of evolution. They start as large top-predators, with big sabre teeth and serrated incisors, but then retreat from this adaptive peak and go on to produce small insectivores and herbivores. It's possible that the inflexibility of mammal carnivore evolution is a mammal thing, not a carnivore thing.
Brocklehurst, N., & Fröbisch, J. 2018. The definition of bioregions in palaeontological studies of diversity and biogeography affects interpretations: Palaeozoic tetrapods as a case study. Frontiers in Earth Sciences (6): 200
- A look at how palaeontologists group their fossil-bearing localities into discrete regions for diversity studies, and how this can affect the results. Also suggests a method for doing this more robustly, coded in R (check out the tutorial!). Even if this specific method doesn't catch on, I hope this paper will bring these issues to wider attention.
Brocklehurst, N. 2018. An examination of the impact of Olson’s Extinction on tetrapods from Texas. PeerJ (6): e4767
- A look at an event I have been arguing about for most of my career. I have been a strong proponent for the idea that Olson's Extinction (between the early and middle Permian) is a genuine event, not an artefact of various sampling/method biases. In this paper I endeavour to address the criticism that the extinction is an artefact of the division of time into bins, thus grouping a long period of extinction into a single event. I show, using a high resolution, well-sampled record from Texas, that the extinction is robust to the binning strategy used.
Brocklehurst, N., Day, M.O. & Fröbisch, J. 2018. Accounting for differences in species frequency distributions when calculating beta diversity in the fossil record. Methods in Ecology and Evolution (9): 1409-1420
- My first creation of a brand new method from scratch, one which I hope will catch on (it does work, honest!): calculating beta diversity with correction for the influence of different-shaped abundance distributions. Without this correction, a more uneven abundance distribution, if incompletely sampled, will give you a lower beta diversity estimate. The method is coded in R, and there's a tutorial on this site. Try it out!
Brocklehurst, N., Day, M.O., Rubidge, B.S. & Fröbisch, J. 2017. Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian. Proceedings of the Royal Society B (284): 20170231
-Yet another paper on Olson's extinction. This one addresses the concern that the extinction is an artefact of the patchy geographic distribution of sampling. At the time of the extinction there is a shift in the sampling from mostly equatorial ecosystems to temperate. Since in the present day temperate latitudes are less diverse than equatorial latitudes (the latitudinal diversity gradient), it has been suggested that this shift in sampling is responsible for the apparent extinction. Here I show that the latitudinal diversity gradient was inverted during the Permian; it was in fact the temperate regions that were more diverse.
Brocklehurst, N., Romano, M. & Fröbisch, J. 2016. Principal component analysis as an alternative treatment for morphometric characters: phylogeny of caseids as a case study. Palaeontology (59): 877-886
-This is the first of my papers that I really felt proud of, and that I hoped would actually start affecting the way people worked. So it's a source of perpetual disappointment to me that it seems to have passed most people by. Its not even acknowledged in recent studies that have actually used principal components as characters in phylogenetic analyses (yes, this is a passive-aggressive gripe that people aren't citing my work when they clearly should). Anyway, its a discussion of the advantages of using principal components as continuous characters in phylogenetic analysis rather than linear measurements or ratios, and also proposes a way of re-scaling continuous characters so that those which show less variation affect the analysis less.
Brocklehurst, N., Kammerer C.F., Benson, R.B.J. 2020. The Origin of Tetrapod Herbivory: Effects on Local Plant Diversity. Proceedings of the Royal Society B (287): 20200124
- A look at how the origin of herbivory affected plant evolution in the Paleozoic. In the present day, herbivores can both enhance and also constrain plant diversity depending on how selective they are; more selective herbivores increase the predation pressure on more plants and reduce diversity, while more generalist herbivores prevent weed-like plants from dominating and give others a chance. The radiation of herbivores at the end of the Carboniferous is found to permanently constrain plant diversity. In particular, the plant diversity crash coincides with the radiation of small herbivores, which tend to be more selective.
Brocklehurst, N. 2019. Therocephalians break the hypercarnviore ratchet. Proceedings of the Royal Society B (286): 20190590
- An idea I'd had in my head for a while (I suggested it as a potential PhD project many moons ago, but switched to diversity) was to compare evolution of mammal carnivores to their therapsid relatives from the Permian and Triassic. Mammal carnivores seem to be very inflexible in their evolution; once they adopt a hypercarnivore specialisation, they stick to it, becoming ever more specialised and larger until extinction. However, therocephalians (a therapsid lineage) show a very different pattern of evolution. They start as large top-predators, with big sabre teeth and serrated incisors, but then retreat from this adaptive peak and go on to produce small insectivores and herbivores. It's possible that the inflexibility of mammal carnivore evolution is a mammal thing, not a carnivore thing.
Brocklehurst, N., & Fröbisch, J. 2018. The definition of bioregions in palaeontological studies of diversity and biogeography affects interpretations: Palaeozoic tetrapods as a case study. Frontiers in Earth Sciences (6): 200
- A look at how palaeontologists group their fossil-bearing localities into discrete regions for diversity studies, and how this can affect the results. Also suggests a method for doing this more robustly, coded in R (check out the tutorial!). Even if this specific method doesn't catch on, I hope this paper will bring these issues to wider attention.
Brocklehurst, N. 2018. An examination of the impact of Olson’s Extinction on tetrapods from Texas. PeerJ (6): e4767
- A look at an event I have been arguing about for most of my career. I have been a strong proponent for the idea that Olson's Extinction (between the early and middle Permian) is a genuine event, not an artefact of various sampling/method biases. In this paper I endeavour to address the criticism that the extinction is an artefact of the division of time into bins, thus grouping a long period of extinction into a single event. I show, using a high resolution, well-sampled record from Texas, that the extinction is robust to the binning strategy used.
Brocklehurst, N., Day, M.O. & Fröbisch, J. 2018. Accounting for differences in species frequency distributions when calculating beta diversity in the fossil record. Methods in Ecology and Evolution (9): 1409-1420
- My first creation of a brand new method from scratch, one which I hope will catch on (it does work, honest!): calculating beta diversity with correction for the influence of different-shaped abundance distributions. Without this correction, a more uneven abundance distribution, if incompletely sampled, will give you a lower beta diversity estimate. The method is coded in R, and there's a tutorial on this site. Try it out!
Brocklehurst, N., Day, M.O., Rubidge, B.S. & Fröbisch, J. 2017. Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian. Proceedings of the Royal Society B (284): 20170231
-Yet another paper on Olson's extinction. This one addresses the concern that the extinction is an artefact of the patchy geographic distribution of sampling. At the time of the extinction there is a shift in the sampling from mostly equatorial ecosystems to temperate. Since in the present day temperate latitudes are less diverse than equatorial latitudes (the latitudinal diversity gradient), it has been suggested that this shift in sampling is responsible for the apparent extinction. Here I show that the latitudinal diversity gradient was inverted during the Permian; it was in fact the temperate regions that were more diverse.
Brocklehurst, N., Romano, M. & Fröbisch, J. 2016. Principal component analysis as an alternative treatment for morphometric characters: phylogeny of caseids as a case study. Palaeontology (59): 877-886
-This is the first of my papers that I really felt proud of, and that I hoped would actually start affecting the way people worked. So it's a source of perpetual disappointment to me that it seems to have passed most people by. Its not even acknowledged in recent studies that have actually used principal components as characters in phylogenetic analyses (yes, this is a passive-aggressive gripe that people aren't citing my work when they clearly should). Anyway, its a discussion of the advantages of using principal components as continuous characters in phylogenetic analysis rather than linear measurements or ratios, and also proposes a way of re-scaling continuous characters so that those which show less variation affect the analysis less.
Full list
Brocklehurst, N., Ford, D.P., & Benson, R.B.J. 2022. Early origins of divergent patterns of morphological evolution on the mammal and reptile stem-lineages. Systematic Biology 71: 1195-1209
Brocklehurst, N. & Benson, R.B.J. 2021. Multiple paths to morphological diversification during the origin of amniotes. Nature Ecology and Evolution 5: 1243-1249
Brocklehurst, N., Panciroli, E., Benevento, G.L. & Benson, R.B.J. 2021. Mammaliaform extinctions as a driver of the morphological radiation of Cenozoic mammals. Current Biology 31: 2955-2963
Brocklehurst, N. 2021. The First Age of Reptiles? Comparing Reptile and Synapsid Diversity, and the Influence of Lagerstätten, During the Carboniferous and Early Permian. Frontiers in Ecology and Evolution 9: 669765
Brocklehurst, N., & Field, D. J. 2021. Macroevolutionary dynamics of dentition in Mesozoic birds reveal no long-term selection towards tooth loss. iScience (24): 102243
Brocklehurst, N., & Haridy, Y. 2021. Do meristic characters used in phylogenetic analysis evolve in an ordered manner? Systematic Biology 70:707-718
Brocklehurst, N. 2020. Olson’s Gap or Olson’s Extinction? A Bayesian tip-dating approach to resolving stratigraphic uncertainty. Proceedings of the Royal Society B (287): 20200154
Brocklehurst, N., Kammerer C.F., Benson, R.B.J. 2020. The Origin of Tetrapod Herbivory: Effects on Local Plant Diversity. Proceedings of the Royal Society B (287): 20200124
Brocklehurst, N., & Benevento, G.L.B. 2020. Dental characters used in phylogenetic analyses of mammals show higher rates of evolution, but not reduced independence. PeerJ (8): e8744
Brocklehurst, N. 2019. Morphological evolution in therocephalians breaks the hypercarnivore ratchet. Proceedings of the Royal Society B (286): 20180590
Grunert, H.R., Brocklehurst, N., & Fröbisch, J. 2019. Diversity and Disparity of Therocephalia: Macroevolutionary Patterns through Two Mass Extinctions. Scientific Reports (9): 5063
MacDougal, M., Brocklehurst, N. & Fröbisch, J. 2019. Species richness and disparity of parareptiles across the end-Permian mass extinction. Proceedings of the Royal Society B (286): 20182572
Lukic-Walther, M., Brocklehurst, N., Kammerer, C.F., & Fröbisch, J. 2018. Diversity patterns of non-mammalian cynodonts (Synapsida, Therapsida) and the impact of taxonomic practice and research history on diversity estimates. Paleobiology (45): 56-69
Brocklehurst, N. & Fröbisch, J. 2018. A re-examination of Milosaurus mccordi, and the evolution of large body size in Carboniferous synapsids. Journal of Vertebrate Paleontology (38): e1508026
Brocklehurst, N., & Fröbisch, J. 2018. The definition of bioregions in palaeontological studies of diversity and biogeography affects interpretations: Palaeozoic tetrapods as a case study. Frontiers in Earth Sciences (6): 200
Brocklehurst, N., Dunne, E.M., Cashmore, D.D., & Fröbisch, J. 2018. Physical and environmental drivers of Paleozoic tetrapod dispersal across Pangaea. Nature Communications (9): 5216
Romano, M., Brocklehurst, N., Manni, R., & Nicosia, U. 2018. Multiphase morphospace saturation in cyrtocrinid crinoids. Lethaia (54): 538-546
MacDougall, M.J., Modesto, S.P., Brocklehurst, N., Verriére, A., Reisz, R.R., and Fröbisch, J. 2018. Response: a reassessment of the taxonomic position of Mesosaurs, and a surprising phylogeny of early amniotes. Frontiers in Earth Science (6): 99
Brocklehurst, N. 2018. An examination of the impact of Olson’s Extinction on tetrapods from Texas. PeerJ (6): e4767
Brocklehurst, N., Day, M.O. & Fröbisch, J. 2018. Accounting for differences in species frequency distributions when calculating beta diversity in the fossil record. Methods in Ecology and Evolution (9): 1409-1420
Dunne, E.M., Close, R.A., Button, D.J., Brocklehurst, N., Cashmore, D.D., Lloyd, G.T. & Butler, R.J. 2018. Diversity change during the rise of tetrapods and the impact of the ‘Carboniferous rainforest collapse’. Proceedings of the Royal Society B (285): 20172730
Romano, M., Brocklehurst, N. & Fröbisch, J. 2018. The postcranial skeleton of Ennatosaurus tecton (Synapsida, Caseidae). Journal of Systematic Palaeontology (16): 1097-1122.
Dunhill, A., Hannisdal, B., Brocklehurst, N. & Benton, M. 2018. On formation-based sampling proxies and why they should not be used to correct the fossil record. Palaeontology (61): 119-132
Romano, M., Brocklehurst, N. & Fröbisch, J. 2017. Discrete and continuous character-based disparity analyses converge to the same macroevolutionary signal: a case study from captorhinids. Scientific Reports (7): 17531
Brocklehurst, N. 2017. Rates of morphological evolution in Captorhinidae: an adaptive radiation of Permian herbivores. PeerJ (5): e3200
Brocklehurst, N., Day, M.O., Rubidge, B.S. & Fröbisch, J. 2017. Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian. Proceedings of the Royal Society B (284): 20170231
Brocklehurst, N. & Fröbisch, J. 2017. A re-examination of the enigmatic Russian tetrapod Phreatophasma aenigmaticum, and its evolutionary implications. Fossil Record (80): 87-93
Brocklehurst, N. & Brink, K. 2017. Selection towards larger body size in both herbivorous and carnivorous synapsids during the Carboniferous. Facets (2): 68–84
Brocklehurst, N., Romano, M. & Fröbisch, J. 2016. Principal component analysis as alternative treatment for morphometric characters: phylogeny of caseids as a case study. Palaeontology (59): 877-886
Verriére, A., Brocklehurst, N. & Fröbisch, J. 2016. Assessing the completeness of the fossil record: comparison of different methods applied to parareptilian tetrapods (Vertebrata: Sauropsida). Paleobiology (42): 680-695
Brocklehurst, N., Reisz, R., Fernandez, V. & Fröbisch, J. 2016. A re-description of “Mycterosaurus” smithae, an Early Permian eothyridid, and an examination the phylogeny of pelycosaurian-grade synapsids. PloS One (11): e0156810
Brocklehurst, N. 2016. Rates and modes of body size evolution in early carnivores and herbivores: a case study from Captorhinidae. PeerJ (4): e1555
Brocklehurst, N., Ruta, M., Müller, J. & Fröbisch, J. 2015. Elevated extinction rates as a trigger for diversification rate shifts: early amniotes as a case study. Scientific Reports (5): 1-10
Brocklehurst, N. 2015. A simulation-based examination of residual diversity estimates as a method of correcting for sampling bias. Palaeontologia Electronica (18.3.7T): 1-15
Brocklehurst, N. & Fröbisch, J. 2014. Current and historical perspectives on the completeness of the fossil record of pelycosaurian-grade synapsids. Palaeogeography, Palaeoclimatology, Palaeoecology (399): 114-126.
Brocklehurst, N., Kammerer, C.F. & Fröbisch, J. 2013. The early evolution of synapsids, and the influence of sampling on their fossil record. Paleobiology (39): 470-490.
Brocklehurst, N., Upchurch, P., Mannion, P.D., O’Connor, J. 2012. The completeness of the fossil record of Mesozoic birds: implications for early avian evolution. PloS One (7): e39056
Brocklehurst, N. & Benson, R.B.J. 2021. Multiple paths to morphological diversification during the origin of amniotes. Nature Ecology and Evolution 5: 1243-1249
Brocklehurst, N., Panciroli, E., Benevento, G.L. & Benson, R.B.J. 2021. Mammaliaform extinctions as a driver of the morphological radiation of Cenozoic mammals. Current Biology 31: 2955-2963
Brocklehurst, N. 2021. The First Age of Reptiles? Comparing Reptile and Synapsid Diversity, and the Influence of Lagerstätten, During the Carboniferous and Early Permian. Frontiers in Ecology and Evolution 9: 669765
Brocklehurst, N., & Field, D. J. 2021. Macroevolutionary dynamics of dentition in Mesozoic birds reveal no long-term selection towards tooth loss. iScience (24): 102243
Brocklehurst, N., & Haridy, Y. 2021. Do meristic characters used in phylogenetic analysis evolve in an ordered manner? Systematic Biology 70:707-718
Brocklehurst, N. 2020. Olson’s Gap or Olson’s Extinction? A Bayesian tip-dating approach to resolving stratigraphic uncertainty. Proceedings of the Royal Society B (287): 20200154
Brocklehurst, N., Kammerer C.F., Benson, R.B.J. 2020. The Origin of Tetrapod Herbivory: Effects on Local Plant Diversity. Proceedings of the Royal Society B (287): 20200124
Brocklehurst, N., & Benevento, G.L.B. 2020. Dental characters used in phylogenetic analyses of mammals show higher rates of evolution, but not reduced independence. PeerJ (8): e8744
Brocklehurst, N. 2019. Morphological evolution in therocephalians breaks the hypercarnivore ratchet. Proceedings of the Royal Society B (286): 20180590
Grunert, H.R., Brocklehurst, N., & Fröbisch, J. 2019. Diversity and Disparity of Therocephalia: Macroevolutionary Patterns through Two Mass Extinctions. Scientific Reports (9): 5063
MacDougal, M., Brocklehurst, N. & Fröbisch, J. 2019. Species richness and disparity of parareptiles across the end-Permian mass extinction. Proceedings of the Royal Society B (286): 20182572
Lukic-Walther, M., Brocklehurst, N., Kammerer, C.F., & Fröbisch, J. 2018. Diversity patterns of non-mammalian cynodonts (Synapsida, Therapsida) and the impact of taxonomic practice and research history on diversity estimates. Paleobiology (45): 56-69
Brocklehurst, N. & Fröbisch, J. 2018. A re-examination of Milosaurus mccordi, and the evolution of large body size in Carboniferous synapsids. Journal of Vertebrate Paleontology (38): e1508026
Brocklehurst, N., & Fröbisch, J. 2018. The definition of bioregions in palaeontological studies of diversity and biogeography affects interpretations: Palaeozoic tetrapods as a case study. Frontiers in Earth Sciences (6): 200
Brocklehurst, N., Dunne, E.M., Cashmore, D.D., & Fröbisch, J. 2018. Physical and environmental drivers of Paleozoic tetrapod dispersal across Pangaea. Nature Communications (9): 5216
Romano, M., Brocklehurst, N., Manni, R., & Nicosia, U. 2018. Multiphase morphospace saturation in cyrtocrinid crinoids. Lethaia (54): 538-546
MacDougall, M.J., Modesto, S.P., Brocklehurst, N., Verriére, A., Reisz, R.R., and Fröbisch, J. 2018. Response: a reassessment of the taxonomic position of Mesosaurs, and a surprising phylogeny of early amniotes. Frontiers in Earth Science (6): 99
Brocklehurst, N. 2018. An examination of the impact of Olson’s Extinction on tetrapods from Texas. PeerJ (6): e4767
Brocklehurst, N., Day, M.O. & Fröbisch, J. 2018. Accounting for differences in species frequency distributions when calculating beta diversity in the fossil record. Methods in Ecology and Evolution (9): 1409-1420
Dunne, E.M., Close, R.A., Button, D.J., Brocklehurst, N., Cashmore, D.D., Lloyd, G.T. & Butler, R.J. 2018. Diversity change during the rise of tetrapods and the impact of the ‘Carboniferous rainforest collapse’. Proceedings of the Royal Society B (285): 20172730
Romano, M., Brocklehurst, N. & Fröbisch, J. 2018. The postcranial skeleton of Ennatosaurus tecton (Synapsida, Caseidae). Journal of Systematic Palaeontology (16): 1097-1122.
Dunhill, A., Hannisdal, B., Brocklehurst, N. & Benton, M. 2018. On formation-based sampling proxies and why they should not be used to correct the fossil record. Palaeontology (61): 119-132
Romano, M., Brocklehurst, N. & Fröbisch, J. 2017. Discrete and continuous character-based disparity analyses converge to the same macroevolutionary signal: a case study from captorhinids. Scientific Reports (7): 17531
Brocklehurst, N. 2017. Rates of morphological evolution in Captorhinidae: an adaptive radiation of Permian herbivores. PeerJ (5): e3200
Brocklehurst, N., Day, M.O., Rubidge, B.S. & Fröbisch, J. 2017. Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian. Proceedings of the Royal Society B (284): 20170231
Brocklehurst, N. & Fröbisch, J. 2017. A re-examination of the enigmatic Russian tetrapod Phreatophasma aenigmaticum, and its evolutionary implications. Fossil Record (80): 87-93
Brocklehurst, N. & Brink, K. 2017. Selection towards larger body size in both herbivorous and carnivorous synapsids during the Carboniferous. Facets (2): 68–84
Brocklehurst, N., Romano, M. & Fröbisch, J. 2016. Principal component analysis as alternative treatment for morphometric characters: phylogeny of caseids as a case study. Palaeontology (59): 877-886
Verriére, A., Brocklehurst, N. & Fröbisch, J. 2016. Assessing the completeness of the fossil record: comparison of different methods applied to parareptilian tetrapods (Vertebrata: Sauropsida). Paleobiology (42): 680-695
Brocklehurst, N., Reisz, R., Fernandez, V. & Fröbisch, J. 2016. A re-description of “Mycterosaurus” smithae, an Early Permian eothyridid, and an examination the phylogeny of pelycosaurian-grade synapsids. PloS One (11): e0156810
Brocklehurst, N. 2016. Rates and modes of body size evolution in early carnivores and herbivores: a case study from Captorhinidae. PeerJ (4): e1555
Brocklehurst, N., Ruta, M., Müller, J. & Fröbisch, J. 2015. Elevated extinction rates as a trigger for diversification rate shifts: early amniotes as a case study. Scientific Reports (5): 1-10
Brocklehurst, N. 2015. A simulation-based examination of residual diversity estimates as a method of correcting for sampling bias. Palaeontologia Electronica (18.3.7T): 1-15
Brocklehurst, N. & Fröbisch, J. 2014. Current and historical perspectives on the completeness of the fossil record of pelycosaurian-grade synapsids. Palaeogeography, Palaeoclimatology, Palaeoecology (399): 114-126.
Brocklehurst, N., Kammerer, C.F. & Fröbisch, J. 2013. The early evolution of synapsids, and the influence of sampling on their fossil record. Paleobiology (39): 470-490.
Brocklehurst, N., Upchurch, P., Mannion, P.D., O’Connor, J. 2012. The completeness of the fossil record of Mesozoic birds: implications for early avian evolution. PloS One (7): e39056
