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Mateus, O., Jacobs L., Polcyn M., Schulp A. S., Vineyard D., Buta Neto A., & Telles Antunes M. (2009).  The oldest African eucryptodiran turtle from the Cretaceous of Angola. Acta Palaeontologica Polonica. 54, 581-588., Number 4 Abstract
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Myers, T. S., Tabor N. J., Jacobs L. L., & Mateus O. (2012).  Palaeoclimate of the Late Jurassic of Portugal: Comparison with the Western United States. Sedimentology. 59(6), 1695–1717., 2012//01/ Abstractmyers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_with_the_western.pdfWebsite

Investigation of the palaeoclimatic conditions associated with Upper Jurassic strata in Portugal and comparison with published palaeoclimate reconstructions of the Upper Jurassic Morrison Formation in western North America provide important insights into the conditions that allowed two of the richest terrestrial faunas of this period to flourish. Geochemical analyses and observations of palaeosol morphology in the informally named Upper Jurassic Lourinhã formation of western Portugal indicate warm and wet palaeoclimatic conditions with strongly seasonal precipitation patterns. Palaeosol profiles are dominated by carbonate accumulations and abundant shrink-swell (vertic) features that are both indicative of seasonal variation in moisture availability. The δ18OSMOW and δDSMOW values of phyllosilicates sampled from palaeosol profiles range from +22·4‰ to +22·7‰ and −53·0‰ to −37·3‰, respectively. These isotope values correspond to temperatures of formation between 32°C and 39°C ± 3°, with an average of 36°C, which suggest surface temperatures between 27°C and 34°C (average 31°C). On average, these surface temperature estimates are 1°C higher than the highest summer temperatures modelled for Late Jurassic Iberia using general circulation models. Elemental analysis of matrix material from palaeosol B-horizons provides proxy (chemical index of alteration minus potassium) estimates of mean annual precipitation ranging from 766 to 1394 mm/year, with an average of approximately 1100 mm/year. Palaeoclimatic conditions during deposition of the Lourinhã formation are broadly similar to those inferred for the Morrison Formation, except somewhat wetter. Seasonal variation in moisture availability does not seem to have negatively impacted the ability of these environments to support rich and relatively abundant faunas. The similar climate between these two Late Jurassic terrestrial ecosystems is probably one of the factors which explains the similarity of their vertebrate faunas.

Myers, T. S., Tabor N. J., Jacobs L. L., & Mateus O. (2012).  Palaeoclimate of the late jurassic of portugal: Comparison with the western united states. Sedimentology. 59, 1695-1717., Number 6 Abstract
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Ceríaco, L. M. P., Gutiérrez E. E., Dubois A., Abdala C. S., Alqarni A. S., Adler K., et al. (2016).  Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences. Zootaxa. 4196(3), 435 - 445., 2016 AbstractWebsite
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Ceríaco, L. M. P., Gutiérrez E. E., Dubois A., Abdala C. S., Alqarni A. S., Adler K., et al. (2016).  Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences. Zootaxa. 4196, 435-445., Number 3 Abstract
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Jacobs, L., Polcyn M., Araújo R., Strganac C., & Mateus O. (2010).  Physical drivers of evolution and the history of the marine tetrapod fauna of Angola. Annual Meeting of the Society of Vertebrate Paleontology. 110A., Jan Abstractjacobs_et_al_mateus_2010_physical_drivers_marine_tetrapod_fauna_of_angola_svp10abstracts.pdf

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Polcyn, M. J., Jacobs L. L., Ara´ujo R., Schulp A. S., & Mateus O. (2014).  Physical drivers of mosasaur evolution. Palaeogeography, Palaeoclimatology, Palaeoecology. 400, 17-27. Abstractpolcyn_et_al_2014_physical_drivers_mosasaurs.pdf

Mosasaurs are marine squamates with a 32.5 million-year history from their appearance at 98 Ma to their extinction at the K-Pg boundary (65.5 Ma). Using a database of 43 generic and 94 species-level taxa, we compare the taxonomic diversity and patterns of morphological disparity in mosasaurs with sea level, sea surface temperature, and stable carbon isotope curves for the Upper Cretaceous to explore factors that may have influenced their evolution. No single factor unambiguously accounts for all radiations, diversification, and extinctions; however, the broader patterns of taxonomic diversification and
morphological disparity point to niche differentiation in a “fishing up” scenario under the influence of “bottom-up” selective pressures. The most likely driving force in mosasaur evolution was high productivity in the Late Cretaceous, driven by tectonically controlled sea levels and climatically controlled ocean stratification and nutrient delivery. When productivity collapsed at the end of the Cretaceous, coincident with bolide impact, mosasaurs became extinct.

Polcyn, M. J., Jacobs L. L., Araújo R., Schulp A. S., & Mateus O. (2014).  Physical drivers of mosasaur evolution. Palaeogeography, Palaeoclimatology, Palaeoecology. 400, 17-27. Abstract
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Araújo, R., Polcyn M., Jacobs L. L., Mateus O., & Schulp A. S. (2011).  Plesiosaur structural extreme from the Maastrichtian of Angola. 71st Annual Meeting of the Society of Vertebrate Paleontology. 63., Jan: Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology Abstractaraujo_et_al_mateus_2011_plesiosaur_extreme_angola_svp11abstracts.pdf

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Araújo, R., Jacobs L., Polcyn M., Mateus O., & Schulp A. (2010).  Plesiosaurs from the Maastrichtian of Bentiaba, Namibe Province, Angola. Society of Vertebrate Paleontology 70th Annual Meeting.. Abstractaraujo_polcyn_mateus__schulp_2010_plesiosaurs_from_maastrichtian_of_angola_svp10abstracts.pdf

Recent excavations at the Maastrichtian locality of Bentiaba, Namibe Province, in the southern part of Angola, have yielded high quality and partially articulated plesiosaur specimens that indicate at least three taxa were present. A new elasmosaurid is the most abundant and well-preserved plesiosaur taxon at Bentiaba. It is known from a complete articulated paddle and other elements of the skeleton, many of which remain to be collected. The most diagnostic elements so far recovered are the complete pelvic and pectoral girdles, which indicate that the Bentiaba elasmosaurid is probably a new genus because it bears an asymmetrical ventral process of the coracoids, a complete cordiform posterior coracoid vacuity, and pronounced excavation of the anterior border of the coracoids, among other characters. A polycotylid is [...]

Jacobs, L. L., Polcyn M. J., Mateus O., Schulp A. S., Gonçalves A. O., & Morais M. L. (2016).  Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast. Memoirs of Museum Victoria. 74, 343–362. Abstractjacobs_et_al_2016_post-gondwana_africa_and_the_vertebrate_history_of_the_angolan_atlantic_coast_343-362_mmv74_jacobs_4_web.pdf

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Jacobs, L. L., Polcyn M. J., Mateus O., Schulp A. S., Gon?alves A. O., & Morais M. L. (2016).  Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast. Memoirs of Museum Victoria. 74, 343-362. Abstract
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Jacobs, L. L., Polcyn M. J., Mateus O. \á\}vio, Schulp A. S., Gon\{\c c\}alves A. \ó\}nio O., & Morais M. L. (2016).  Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast. Memoirs of Museum Victoria. 74, 343\–\}362. Abstract
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Jacobs, L.  L., Sousa N., Goncalves A.  O., Mateus O., Polcyn M.  J., & Schulp A.  S. (2020).  Projecto PaleoAngola: Geoheritage and Conservation Paleobiology as Science for Development in Angola. AGU Fall Meeting Abstracts. 2020, SY048-05. Abstractprojecto_paleoangola__geoheritage.pdf

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Tschopp, E., Mateus O., Kosma R., Sander M., Joger U., & Wings O. (2014).  A specimen-level cladistic analysis of Camarasaurus (Dinosauria, Sauropoda) and a revision of camarasaurid taxonomy. Journal of Vertebrate Paleontology. Program and Abstracts, 2014, 241-242.tschopp_et_al._2014_a_specimen-level_cladistic_analysis_of_camarasaurus.pdf
Strganac, C., Jacobs L. L., Polcyn M. J., Ferguson K. M., Mateus O., Gonçalves O. A., Morais M. - L., & da Silva Tavares T. (2015).  Stable oxygen isotope chemostratigraphy and paleotemperature regime of mosasaurs at Bentiaba, Angola. Netherlands Journal of Geosciences. FirstView, 1–7., 2 Abstractstrganac_etal2015_stable_oxigen_isotopes.pdfWebsite

ABSTRACT Stable oxygen isotope values of inoceramid marine bivalve shells recovered from Bentiaba, Angola, are utilised as a proxy for paleotemperatures during the Late Cretaceous development of the African margin of the South Atlantic Ocean. The δ18O values derived from inoceramids show a long-term increase from –3.2‰ in the Late Turonian to values between –0.8 and –1.8‰ in the Late Campanian. Assuming a constant oceanic δ18O value, an ∼2‰ increase may reflect cooling of the shallow marine environment at Bentiaba by approximately 10°. Bentiaba values are offset by about +1‰ from published records for bathyal Inoceramus at Walvis Ridge. This offset in δ18O values suggests a temperature difference of ∼5° between coastal and deeper water offshore Angola. Cooler temperatures implied by the δ18O curve at Bentiaba coincide with the stratigraphic distribution of diverse marine amniotes, including mosasaurs, at Bentiaba.

Strganac, C., Jacobs L. L., Polcyn M. J., Ferguson K. M., Mateus O., Gon?alves A. O., Morais M. - L., & da Silva Tavares T. (2014).  Stable oxygen isotope chemostratigraphy and paleotemperature regime of mosasaurs at Bentiaba, Angola. Geologie en Mijnbouw/Netherlands Journal of Geosciences. 94, 137-143., Number 1 Abstract
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Jacobs, L. L., Morais M. L., Schulp A. S., Mateus O., & Polcyn M. J. (2006).  Systematic Position and Geological Context of Angolasaurus (Mosasauridae) and a New Sea Turtle from the Cretaceous of Angola. Journal of Vertebrate Paleontology, 26 (Suppl. To 3). 81. Abstract
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Jacobs, L. L., Polcyn M. J., Mateus O., Schulp A., Ferguson K., Scotese C., Jacobs B. F., Strganac C., Vineyard D., Myers T. S., & Morais M. L. (2010).  Tectonic Drift, Climate, and Paleoenvironment of Angola Since the Cretaceous. AGU Fall Meeting Abstracts, 1:. 02., Jan Abstractjacobs_polcyn_mateus_et_al_2010_tectonic_drift_climate_and_paleoenvironment_of_angola_since_the_cretaceous.pdf

Africa is the only continent that now straddles arid zones located beneath the descending limbs of both the northern and southern Hadley cells, and it has done so since it became a distinct continent in the Early Cretaceous. Since that time, Africa has drifted tectonically some 12 degrees north and rotated approximately 45 degrees counterclockwise. This changing latitudinal setting and position of the landmass under the relatively stable Hadley Cells is manifested as southward migration of climatic zones over the past 132 million years. Data from kerogen, X-ray diffraction analysis of sedimentary matrix, carbon isotopes from shell samples and tooth enamel,new 40Ar/39Ar radiometric dates, pollen and plant macrofossils, and fossil vertebrates indicate a productive upwelling system adjacent to a coastal desert since the opening of the South Atlantic Ocean; however, the position of the coastal desert has migrated southward as Africa drifted north, resulting in today's Skeleton Coast and Benguela Current. This migration has had a profound effect on the placement of the West African coast relative to areas of high marine productivity and resulting extensive hydrocarbon deposits, on the placement of arid zones relative to the continent especially the Skeleton Coast desert, on the climatic history of the Congo Basin (which shows a Late Cretaceous decrease in aridity based on the relative abundance of analcime in the Samba core), and in reducing the southern temperate region of Africa from 17% of continental area during the Cretaceous to 2% today. We show here that these related geographic and environmental changes drove ecological and evolutionary adjustments in southern African floras and faunas, specifically with respect to the distribution of anthropoid primates, the occurrence of modern relicts such as the gnetalean Welwitschia mirabilis, endemism as in the case of ice plants, and mammalian adaption to an open environment as in springhares. Africa's tectonic drift through climate zones has been a first-order environmental determinant since the Early Cretaceous.

Polcyn, M. J., Jacobs L. L., Schulp A. S., Mateus O., & Araújo R. (2015).  Tethyan and Weddellian biogeographic mixing in the Maastrichtian of Angola. Annual Meeting of the Society of Vertebrate Paleontology. 196., Dallas, TXpolcyn_etal2015_mix_fauna_angola_svp_abstract.pdf
Polcyn, {M. J. }, Jacobs L. L., Schulp A. S., & Mateus O. (2015).  Tethyan and Weddellian biogeographic mixing in the Maastrichtian of Angola. : Journal of Vertebrate Paleontology Abstract
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Polcyn, M. J., Jacobs L. L., Schulp A. S., & Mateus O. (2015).  Trolling the Cretaceous Seas: Marine Amniotes of Two West Coast Margins. Geological Society of America Annual Meeting. 55.: Geological Society of America Abstracts with Programs. Vol. 47, No. 4, p.55 Abstract

In this session we review the Upper Cretaceous marine amniote records from the west coasts of North America and Africa. Recent work by our group in Angola, on the west coast of Africa, has opened up new fossiliferous localities, producing well-preserved turtles, plesiosaurs, and mosasaurs, ranging in age from Late Turonian to Late Maastrichtian. These African localities were deposited in arid latitudes and highly productive upwelling zones along the passive margin of a growing South Atlantic Ocean. The fossil record of Cretaceous marine amniotes from the West Coast of North America is relatively meager when compared to the African record and the prolific fossil beds laid down in the epicontinental seas of the Western Interior Seaway and northern Europe. Nonetheless, these localities provide an important glimpse of a marine ecosystem that developed on the active margins of a deep ocean basin. Historically considered to be depauperate and endemic, the west coast fauna was characterized by unusual forms such as Plotosaurus, arguably one of the most derived mosasaurs; however, in recent years, additional taxa have been described, revealing species diversity and ecological partitioning within these communities and in some cases, faunal interchange with other regions. The large quantity of well-preserved fossils from the west coast of Africa is influenced in part by its paleogeographic position, deposited within highly productive areas of Hadley Cell controlled upwelling zones. By contrast, the North American west coast localities have been deposited in temperate and higher latitudes since the Late Cretaceous. Nonetheless, the North American and African faunas share some common characteristics in a possessing a mix of endemic and more cosmopolitan forms. Habitat partitioning reflected in tooth form and body size is comparable between the Angolan and the North American west coast, and there is remarkable convergence in taxa which appear to exploit certain like-niches.

Polcyn, {M. J. }, Jacobs {L. L. }, Schulp {A. S. }, & Mateus O. (2015).  Trolling the Cretaceous Seas: Marine Amniotes of Two West Coast Margins. : Geological Society of America Abstracts with Programs. Vol. 47, No. 4, p.55 Abstract

In this session we review the Upper Cretaceous marine amniote records from the west coasts of North America and Africa. Recent work by our group in Angola, on the west coast of Africa, has opened up new fossiliferous localities, producing well-preserved turtles, plesiosaurs, and mosasaurs, ranging in age from Late Turonian to Late Maastrichtian. These African localities were deposited in arid latitudes and highly productive upwelling zones along the passive margin of a growing South Atlantic Ocean. The fossil record of Cretaceous marine amniotes from the West Coast of North America is relatively meager when compared to the African record and the prolific fossil beds laid down in the epicontinental seas of the Western Interior Seaway and northern Europe. Nonetheless, these localities provide an important glimpse of a marine ecosystem that developed on the active margins of a deep ocean basin. Historically considered to be depauperate and endemic, the west coast fauna was characterized by unusual forms such as Plotosaurus, arguably one of the most derived mosasaurs; however, in recent years, additional taxa have been described, revealing species diversity and ecological partitioning within these communities and in some cases, faunal interchange with other regions. The large quantity of well-preserved fossils from the west coast of Africa is influenced in part by its paleogeographic position, deposited within highly productive areas of Hadley Cell controlled upwelling zones. By contrast, the North American west coast localities have been deposited in temperate and higher latitudes since the Late Cretaceous. Nonetheless, the North American and African faunas share some common characteristics in a possessing a mix of endemic and more cosmopolitan forms. Habitat partitioning reflected in tooth form and body size is comparable between the Angolan and the North American west coast, and there is remarkable convergence in taxa which appear to exploit certain like-niches.

Schulp, A. S., Polcyn M. J., Mateus O., & Jacobs L. L. (2013).  Two rare mosasaurs from the Maastrichtian of Angola and the Netherlands. Netherlands Journal of Geosciences — Geologie en Mijnbouw. 92(1), 3-10. Abstractschulp_et_al_2013_two_rare_mosasaurs_from_the_maastrichtian_of_angola__njg-92-1-schulp.pdf

We report here the addition of two rare mosasaur taxa to the Maastrichtian marine amniote fauna of Angola. The new specimens include a dentary fragment referable to the large carnivore Prognathodon saturator and an isolated tooth of the small durophage Carinodens belgicus. Both were recovered from Maastrichtian outcrops in southern Angola in 2011. Additionally, a complete posterior mandibular unit of a large mosasaur from the type Maastrichtian of The Netherlands, collected some time prior to 1879 and previously identified as ‘Mosasaurus giganteus’, is described and reassigned here to Prognathodon saturator; historical issues surrounding the taxonomic attribution of this specimen are clarified. The new material extends the known geographic distribution of Prognathodon saturator and Carinodens belgicus.

Schulp, A. S., Polcyn M. J., Mateus O., & Jacobs L. L. (2013).  Two rare mosasaurs from the Maastrichtian of Angola and the Netherlands. Geologie en Mijnbouw/Netherlands Journal of Geosciences. 92, 3-10., Number 1 Abstract
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Jackson, Y. J., Economos R. C., Jacobs L. L., Mateus O., & Gonçalves A. O. (2020).  When dinosaurs walked through diamonds: constraining the age of Early Cretaceous footprints in volcanic crater sediments. 54th Annual GSA South-Central Section Meeting 2020. , Fort Worth: Geological Society of America Abstracts with Programs. Vol. 52, No. 1jackson_et_al_2020_abstract__when_dinosaurs_walked_through_diamonds__gsa.pdf
Jackson, Y., Economos R., Jacobs L., Mateus O., & Gonçalves A. O. (2021).  When Dinosaurs Walked Through Diamonds: Constraining the Age of Early Cretaceous Footprints in Volcanic Crater Sediments. SMU Journal of Undergraduate Research. 6(1), : DOI: https://doi.org/ 10.25172/jour.6.1.1 Available at: https://scholar.smu … Abstractwhen_dinosaurs_walked_through_diamonds.pdf

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