Angola - Africa

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Mateus, O., Callapez P. M., Polcyn M. J., Schulp A. S., Gonçalves A. O., & Jacobs L. L. (2019).  O registo fóssil da biodiversidade em Angola ao longo do tempo: uma perspectiva paleontológica. (Huntley B.J., Russo V., Lages F., Ferrand N., Ed.).Biodiversidade de Angola: Ciência e Conservação - Uma Síntese Moderna. 89-116., Porto: Arte & Ciência Abstractmateus_et_al_2019_paleobiodiversidade_angola.pdf

Este capítulo apresenta uma visão geral da paleobiodiversidade alfa de Angola com base no registo fóssil disponível, o qual se limita às rochas sedimentares, a sua idade variando entre o Pré‑Câmbrico e o pre‑
sente. O período geológico com a maior paleobiodiversidade no registo fóssil angolano é o Cretácico, com mais de 80% do total dos táxones fósseis conhecidos, especialmente moluscos marinhos, sendo estes na sua maioria
amonites. Os vertebrados representam cerca de 15% da fauna conhecida e cerca de um décimo destes são espécies descritas pela primeira vez com base em espécimes de Angola.

Schulp, A. S., Mateus O., Polcyn M., Gonçalves A., & Jacobs L. L. (2019).  Angola and its role in the paleobiogeography of Gondwana. Journal of Vertebrate Paleontology, Program and Abstracts. 188.schulp_et_al_2019_angola_svp_abstract.pdf
Mateus, O., Marzola M., Schulp A. S., Jacobs L. L., Polcyn M. J., Pervov V., Gonçalves A. O., & Morais M. L. (2017).  Angolan ichnosite in a diamond mine shows the presence of a large terrestrial mammaliamorph, a crocodylomorph, and sauropod dinosaurs in the Early Cretaceous of Africa. Palaeogeography, Palaeoclimatology, Palaeoecology. 471, 220 - 232. Abstractmateus_et_al_2017_angolan_ichnosite_catoca.pdfWebsite

Abstract We report here new and the first mammaliamorph tracks from the Early Cretaceous of Africa. The tracksite, that also bears crocodylomorph and sauropod dinosaurian tracks, is in the Catoca diamond mine, Lunda Sul Province, Angola. The mammaliamorph tracks have a unique morphology, attributed to Catocapes angolanus ichnogen. et ichnosp. nov. and present an anterolateral projection of digit I and V. The tracks with an average length of 2.7 cm and width of 3.2 cm are the largest mammaliamorph tracks known from the Early Cretaceous unmatched in size in the skeletal fossil record. The crocodylomorph trackways and tracks are attributed to Angolaichnus adamanticus ichnogen. et ichnosp. nov. (‘ichnofamily’ Batrachopodidae) and present a functionally pentadactyl pes, an extremely outwardly rotated handprint, and an unusual tetradactyl and plantigrade manus. One medium-sized sauropod dinosaur trackway preserved skin impressions of a trackmaker with stride length of 1.6 m; a second is that of a small-sized sauropod trackmaker with a pace length of 75 cm.

Myers, T. S., Polcyn M. J., Mateus O., Vineyard D. P., Gonçalves A. O., & Jacobs L. L. (2017).  A new durophagous stem cheloniid turtle from the lower Paleocene of Cabinda, Angola. Papers in Palaeontology. 2017, 1-16. Abstractnew_durophagous_stem_cheloniid_turtle_from_the_lower_paleocene_of_cabinda_angola.pdfWebsite

A new stem cheloniid turtle, Cabindachelys landanensis, gen. et sp. nov., is represented by a nearly complete skull and partial hyoid collected in lower Paleocene shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda, Angola. A partial chelonioid carapace previously reported from this locality is referred here to C. landanensis. Cabindachelys landanensis possesses clear synapomorphies of Pan-Cheloniidae, including a rod-like rostrum basisphenoidale, V-shaped basisphenoid crest, and secondary palate, but also retains a reduced foramen palatinum posterius, unlike most other pan-cheloniids. Phylogenetic analysis suggests that C. landanensis forms a weakly-supported clade with Erquelinnesia gosseleti, Euclastes acutirostris, Euclastes wielandi and Terlinguachelys fischbecki, although a close relationship between the protostegid T. fischbecki and these durophagous pan-cheloniids is unlikely. The Paleocene–Eocene strata near Landana have produced a number of turtle fossils, including the holotype specimen of the pleurodire Taphrosphys congolensis. A turtle humerus collected c. 1 m above the holotype skull of C. landanensis differs from humeri of chelonioids and Taphrosphys, indicating that a third turtle taxon is present at Landana. Cheloniid fossil material is rare in the Landana assemblage, in comparison with the abundant remains of Taphrosphys congolensis found throughout the stratigraphic section. This disparity implies that C. landanensis preferred open marine habitats, whereas Taphrosphys congolensis spent more time in nearshore environments. The appearance of new durophagous species such as C. landanensis in the early Paleocene reflects the rapid radiation of pan-cheloniids as they diversified into open niches following the K–Pg extinction.

Polcyn, M. J., Bardet N., Amaghzaz M., Gonçalves O. A., Jourani E., Kaddumi H. F., Lindgren J., Mateus O., Meslouhf S., Morais M. L., Pereda-Suberbiola X., Schulp A. S., Vincent P., & Jacobs L. L. (2016).  An extremely derived plioplatecarpine mosasaur from the Maastrichtian of Africa and the Middle East. 5th Triennial Mosasaur Meeting- a global perspective on Mesozoic marine amniotes. 16-20(May 16-20, 2016), May 16-20, 2016., Uppsala, Sweden: Museum of Evolutiom, Uppsala University. Abstractpolcyn_et_al_2016_extremely_derived_mosasaur.pdf

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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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Myers, T. S., Mateus O., Polcyn M. J., Vineyard D., & Jacobs L. L. (2016).  A new chelonioid turtle from the Paleocene of Cabinda, Angola. Annual Meeting of the Society of Vertebrate Paleontology. 194.: Journal of Vertebrate Paleontology, Program and Abstracts, 2016 Abstractmyers_etal_2016_chelonoid_angola_turtle_svp_abstract.pdf

We report a new chelonioid turtle on the basis of a nearly complete skull collected in lower Paleocene, shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda Province, Angola. Chelonioid material previously reported from this locality is likely referable to this new taxon. The well-preserved skull is missing the left quadrate, squamosal, and prootic, both opisthotics, and the mandible. The skull possesses a rod-like basisphenoid rostrum, which is a synapomorphy of Chelonioidea, but it differs from other chelonioid skulls in that the contact between the parietal and squamosal is absent, and the posterior palatine foramen is present. Phylogenetic analysis recovers the new taxon as a basal chelonioid. The Paleocene– Eocene strata near Landana have produced a wealth of turtle fossils, including the holotype of the pleurodire Taphrosphys congolensis. A turtle humerus collected from the Landana locality differs morphologically from the humeri of chelonioids and Taphrosphys, indicating the presence of a third taxon. Chelonioid fossil material in the Landana assemblage is rare compared to the abundant fragmentary remains of Taphrosphys that are found throughout the stratigraphic section. This disparity in abundance suggests the new chelonioid taxon preferred open marine habitats, whereas Taphrosphys frequented nearshore environments.

Araújo, R., Polcyn M. J., Schulp A. S., Mateus O., Jacobs L. L., Gonçalves O. A., & Morais M. - L. (2015).  A new elasmosaurid from the early Maastrichtian of Angola and the implications of girdle morphology on swimming style in plesiosaurs. Netherlands Journal of Geosciences. FirstView, 1–12., 1 Abstractaraujo_et_al_2015_a_new_elasmosaurid_from_the_early_maastrichtian_of_angola.pdfWebsite

ABSTRACT We report here a new elasmosaurid from the early Maastrichtian at Bentiaba, southern Angola. Phylogenetic analysis places the new taxon as the sister taxon to Styxosaurus snowii, and that clade as the sister of a clade composed of (Hydrotherosaurus alexandrae (Libonectes morgani + Elasmosaurus platyurus)). The new taxon has a reduced dorsal blade of the scapula, a feature unique amongst elasmosaurids, but convergent with cryptoclidid plesiosaurs, and indicates a longitudinal protraction-retraction limb cycle rowing style with simple pitch rotation at the glenohumeral articulation. Morphometric phylogenetic analysis of the coracoids of 40 eosauropterygian taxa suggests that there was a broad range of swimming styles within the clade.

Araújo, R., Polcyn M. J., Lindgren J., Jacobs L. L., Schulp A. S., Mateus O., Gonçalves O. A., & Morais M. - L. (2015).  New aristonectine elasmosaurid plesiosaur specimens from the Early Maastrichtian of Angola and comments on paedomorphism in plesiosaurs. Netherlands Journal of Geosciences. FirstView, 1–16., 2 Abstractaraujo_et_al_2015_paedomorphism-libre.pdfWebsite

ABSTRACT New elasmosaurid plesiosaur specimens are described from the Early Maastrichtian of Angola. Phylogenetic analyses reconstruct the Angolan taxon as an aristonectine elasmosaurid and the sister taxon of an unnamed form of similar age from New Zealand. Comparisons also indicate a close relationship with an unnamed form previously described from Patagonia. All of these specimens exhibit an ostensibly osteologically immature external morphology, but histological analysis of the Angolan material suggests an adult with paedomorphic traits. By extension, the similarity of the Angolan, New Zealand and Patagonian material indicates that these specimens represent a widespread paedomorphic yet unnamed taxon.

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.