Profile
Postdoctoral Fellow.
Understanding the biosedimentary record using networks.
Publications
Calatayud, Joaquín; Bernardo-Madrid, Rubén; Neuman, Magnus; Rojas, Alexis; Rosvall, Martin
Exploring the solution landscape enables more reliable network community detection Journal Article
In: Phys. Rev. E, vol. 100, pp. 052308, 2019.
@article{PhysRevE.100.052308,
title = {Exploring the solution landscape enables more reliable network community detection},
author = {Joaquín Calatayud and Rubén Bernardo-Madrid and Magnus Neuman and Alexis Rojas and Martin Rosvall},
url = {https://link.aps.org/doi/10.1103/PhysRevE.100.052308},
doi = {10.1103/PhysRevE.100.052308},
year = {2019},
date = {2019-11-01},
journal = {Phys. Rev. E},
volume = {100},
pages = {052308},
publisher = {American Physical Society},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rojas, Alexis; Sandy, Michael R.
In: Cretaceous Research, 2018.
@article{Rojas2018,
title = {Early Cretaceous (Valanginian) brachiopods from the Rosablanca Formation, Colombia, South America: Biostratigraphic significance and paleogeographic implications},
author = {Alexis Rojas and Michael R. Sandy},
url = {https://www.sciencedirect.com/science/article/pii/S0195667118303665},
doi = {10.1016/j.cretres.2018.12.011},
year = {2018},
date = {2018-12-18},
journal = {Cretaceous Research},
abstract = {The Mesozoic fossil record of brachiopods in northern South America is relatively scarce and their biogeographical history is not well understood. Cretaceous brachiopods in this region are restricted to carbonate platforms of Colombia. Here we examine the brachiopod fauna from the middle part of the Rosablanca Formation near the town of Zapatoca, Eastern Cordillera of Colombia. We describe Sellithyris elizabetha nov. sp. combining traditional morphometrics and serial sectioning. This new terebratulide species shows morphological similarities with other species of the genus Sellithyris, including a Valanginian species from the ancient Gulf of Mexico. Using a semi-quantitative taphonomic analysis, we identified reworked specimens restricted to a single stratigraphic horizon, and consistent with a large-scale erosional hiatus that may affect the biochronology of the Rosablanca Formation. In addition, phosphatic shells of the lingulide Lingularia sp. were recovered from two stratigraphic horizons and are valuable for local correlations. Although much of the material is fragmentary, it represents the oldest occurrences of Cretaceous lingulides in the region so far. Lingulide brachiopods have traditionally been considered as rare elements in Cretaceous near-shore marine communities, however, the material reported here suggests that they may have been common locally.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rojas, Alexis; Portell, Roger W; Kowalewski, Michał
The post-Palaeozoic fossil record of drilling predation on lingulide brachiopods Journal Article
In: Lethaia, vol. 50, no. 2, pp. 296–305, 2017, ISSN: 00241164.
@article{rojas_post-palaeozoic_2017,
title = {The post-Palaeozoic fossil record of drilling predation on lingulide brachiopods},
author = {Alexis Rojas and Roger W Portell and Michał Kowalewski},
url = {http://doi.wiley.com/10.1111/let.12198},
doi = {10.1111/let.12198},
issn = {00241164},
year = {2017},
date = {2017-01-01},
urldate = {2017-04-03},
journal = {Lethaia},
volume = {50},
number = {2},
pages = {296--305},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rojas, Alexis; Patarroyo, Pedro; Mao, Liang; Bengtson, Peter; Kowalewski, Michał
Global biogeography of Albian ammonoids: A network-based approach Journal Article
In: Geology, vol. 45, no. 7, pp. 659–662, 2017, ISSN: 0091-7613, 1943-2682.
@article{rojas_global_2017,
title = {Global biogeography of Albian ammonoids: A network-based approach},
author = {Alexis Rojas and Pedro Patarroyo and Liang Mao and Peter Bengtson and Michał Kowalewski},
url = {http://geology.gsapubs.org/lookup/doi/10.1130/G38944.1},
doi = {10.1130/G38944.1},
issn = {0091-7613, 1943-2682},
year = {2017},
date = {2017-01-01},
urldate = {2017-06-22},
journal = {Geology},
volume = {45},
number = {7},
pages = {659--662},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rojas, Alexis; Hendy, Austin; Dietl, Gregory
Edge-drilling behavior in the predatory gastropod Notocochlis unifasciata (Lamarck, 1822) (Caenogastropoda, Naticidae) from the Pacific coast of Panama: taxonomic and biogeographical implications Journal Article
In: Vita Malacologica, vol. 13, pp. 63–72, 2015.
@article{rojas_edge-drilling_2015,
title = {Edge-drilling behavior in the predatory gastropod Notocochlis unifasciata (Lamarck, 1822) (Caenogastropoda, Naticidae) from the Pacific coast of Panama: taxonomic and biogeographical implications},
author = {Alexis Rojas and Austin Hendy and Gregory Dietl},
year = {2015},
date = {2015-01-01},
journal = {Vita Malacologica},
volume = {13},
pages = {63--72},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rojas, Alexis; Gracia, Adriana; Patarroyo, Pedro
Brachiopods from off the San Bernardo Archipelago (Colombian Caribbean), with comments on specific synonymies in Tichosina, Cooper, 1977 Journal Article
In: Zootaxa, vol. 3914, no. 1, pp. 55, 2015, ISSN: 1175-5334, 1175-5326.
@article{rojas_brachiopods_2015,
title = {Brachiopods from off the San Bernardo Archipelago (Colombian Caribbean), with comments on specific synonymies in Tichosina, Cooper, 1977},
author = {Alexis Rojas and Adriana Gracia and Pedro Patarroyo},
url = {http://biotaxa.org/Zootaxa/article/view/zootaxa.3914.1.3},
doi = {10.11646/zootaxa.3914.1.3},
issn = {1175-5334, 1175-5326},
year = {2015},
date = {2015-01-01},
urldate = {2015-05-07},
journal = {Zootaxa},
volume = {3914},
number = {1},
pages = {55},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Schemm-Gregory, Mena; Rojas-Briceño, Alexis; Patarroyo, Pedro; Jaramillo, Carlos
First report of Hadrosia Cooper, 1983 in South America and its biostratigraphical and palaeobiogeographical implications Journal Article
In: Cretaceous Research, vol. 34, pp. 257–267, 2012, ISSN: 01956671.
@article{schemm-gregory_first_2012,
title = {First report of Hadrosia Cooper, 1983 in South America and its biostratigraphical and palaeobiogeographical implications},
author = {Mena Schemm-Gregory and Alexis Rojas-Briceño and Pedro Patarroyo and Carlos Jaramillo},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0195667111001832},
doi = {10.1016/j.cretres.2011.11.005},
issn = {01956671},
year = {2012},
date = {2012-01-01},
urldate = {2015-09-08},
journal = {Cretaceous Research},
volume = {34},
pages = {257--267},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Alexis is a geologist and a paleontologist. He was born in Colombia, where he received a bachelor’s in biology and geology from public universities. After graduation, he joined the Smithsonian Tropical Research Institute, where he assisted in the Panama Geology Project. After four years of hands-on experience of rocks and fossils in Panama, he enrolled in the Department of Geological Sciences at the University of Florida and worked at the Florida Museum of Natural History with Michał Kowalewski. He received his PhD in Geology with a minor in Geography in 2017.
Alexis’ research interest is focused on understanding the complex interactions between plate tectonics, climate and the biosedimentary record at basin and global scales. He uses an integrative research approach that bridges stratigraphy, paleobiology and network science to address specific questions on spatiotemporal aspects of both the fossil and rock record: How did the tectonic evolution of the Ocean basins influence the spatial structuring of the marine bioprovinces? How do marine bioprovinces respond to major climatic changes that occur over evolutionary timescales?
Alexis enjoys working with Colombian students and professors on Geoheritage conservation, promoting the use of paleontological collections into scientific and education environments, as well as its appreciation by the academic community and the public in general. In his free time, he also enjoys watching road cycling and playing soccer.
Current Projects
Mapping global marine bioprovinces throughout the Phanerozoic.
Martin Rosvall (IceLab) and Lucy Chang (Smithsonian).
Mapping network flows through sedimentary deposits from the Quaternary of the Po Plain (Italy).
Martin Rosvall (IceLab), Michal Kowalewski (Florida Museum of Natural History), and Daniele Scarponi and Michele Azzarone (University of Bologna).
Characterizing shell-drilling gastropod predation using spatial point process modeling.
Greg Dietl (Cornell University), Austin Hendy (Natural History Museum of Los Angeles County) and Jason Blackburn (Emerging Pathogens Institute, UF).
Geoheritage conservation in Colombia.
Yerly Barrera-Huertas (undergraduate student), Andrés Moreno-Ayala (undergraduate student), Martha García (Universidad Pedagógica Nacional de Colombia.
The Latest Posts
Read Alexis’ summaries of his science and other posts here
Gradual changes triggered historical shift in marine fauna
Gradual changes triggered historical shift in marine fauna Large asteroids or comets hitting Earth, massive volcanic eruptions and other single, deadly events are usually the focus for scientists seeking to reconstruct [...]
The distribution of vertebrate animals redefines temperate and cold climate regions
The distribution of vertebrate animals redefines temperate and cold climate regions The distribution of vegetation is routinely used to classify climate regions worldwide, yet whether these regions are relevant to other [...]
SPPAT: Spatial point pattern analysis of traces
SPPAT: Spatial point pattern analysis of traces Site-selectivity patterns of drilling predators revealed by spatial point pattern analysis Trace fossils left by predators on skeletons of their prey, [...]
Hive Talk Board: An example of poor science communication that deserves to be told: Aftermath of the ‘Panama debate’ with Alexis Rojas
An example of poor science communication that deserves to be told: The Aftermath of the 'Panama debate' with Alexis Rojas Hive Talk Snippet Alexis talked about the Isthmus of Panama, its [...]
Spatial distribution of ancient marine faunas
Spatial distribution of ancient marine faunas The problem Organisms living in the same region are what defines a biogeographic province, or bioprovince. Finding the boundaries between these bioprovinces is an [...]