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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.

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.

Mateus, O., Jacobs L. L., Polcyn M. J., Myers T. S., & Schulp A. S. (2015).  The fossil record of testudines from angola from the turonian to oligocene. Society of Vertebrate Paleontology Annual Meeting. 177., Dallasmateus_et_al_2015_testudines_angola_svp_abstract.pdf
Mateus, O., Polcyn M. J., Jacobs L. L., Araújo R., Schulp A. S., Marinheiro J., Pereira B., & Vineyard D. (2012).  Cretaceous amniotes from Angola: dinosaurs, pterosaurs, mosasaurs, plesiosaurs, and turtles. V Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno. 71-105., Salas de los Infantes, Burgos Abstractmateus_et_al_2012_amniotes_from_angola_cretaceous_amniotes_from_angola_dinosaurs_pterosaurs_mosasaurs.pdf

Although rich in Cretaceous vertebrate fossils, prior to 2005 the amniote fossil record of Angola was poorly known. Two horizons and localities have yielded the majority of the vertebrate fossils collected thus far; the Turonian Itombe Formation of Iembe in Bengo Province and the Maastrichtian Mocuio Formation of Bentiaba in Namibe Province. Amniotes of the Mesozoic of Angola are currently restricted to the Cretaceous and include eucryptodire turtles, plesiosaurs, mosasaurs, pterosaurs, and dinosaurs. Recent collecting efforts have greatly expanded our knowledge of the amniote fauna of Angola and most of the taxa reported here were unknown prior to 2005.

Marinheiro, J., & Mateus O. (2011).  Occurrence of the marine turtle Thalassemys in the Kimmeridgian of Oker, Germany. 71st Annual Meeting of the Society of Vertebrate Paleontology. 151., Jan: Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology Abstractmarinheiro__mateus_2011_turtle_thalassemys_oker_germany_svp11abstracts.pdf

A partial chelonian was collected from the Langenberg Formation quarry of Oker (near Goslar, Lower Saxony, Germany). The amniotes from this formation include other chelonians (possible Plesiochelyidae), the sauropod Europasaurus holgeri, theropods (Velociraptorinae), crocodylomorphs (Atoposauridae, Theriosuchus pusillus, Goniopholis simus, Machimosaurus hugii, Steneosaurus brevirostris) and pterosaurs (Dsungapteridae, ?Ornithocheiroidea, ?Ctenochasmatidae).

The reported specimen, DFMMh/FV 296, includes a skull part (articulated quadrate, squamosal, basisphenoid, and pterygoid), a disarticulated 40 cm long partial carapace, plastron, and one cervical vertebra.

The carapace bears fontanelles, trapezoidal suprapygal with straight edges, small last neurals

a plicated longitudinal pattern in the proximal end of the costals originating on the posterior side of the scute sulci and dissipating posteriorly, wide central opening in the plastron, xiphiplastra with little or no contact between each other, and both the hyo- and hypoplastron have digit-form buttress projections.

The specimen has a central plastra fontanelle, which is regarded as a feature of the clade including [....], Santanachelys, and Thalassemys. DFMMh/FV 296 differs from

edges and xiphiplastron participation in the central fontanelle is autapomorphic for the Thalassemys genus. A large central fontanelle with hyo and hypoplastron polygonal medial
contact between xiphiplastra and reduced size of the two last neural plates is shared between T. hugii and the Oker specimen. DFMMh/FV 296 differs from this species due to the presence of plastral projections. The different shape of the plastron (no polygonal-like margins or hyo- and hypoplastron projections) suggests that T. moseri [....]
ent genus. Therefore, we can assign this specimen to Thalassemys sp.

Mateus, O., Jacobs L., Polcyn M., Schulp A. S., Vineyard D., Neto A. B., & Antunes M. T. (2009).  The oldest African eucryptodiran turtle from the Cretaceous of Angola. Acta Palaeontologica Polonica. 54, 581-588., Jan: Univ Agostinho Neto, Univ Nova Lisboa, Museu Lourinha, Acad Ciencias Lisboa, Nat Hist Museum Maastricht, So Methodist Univ Abstractmateus_et_al_2009_the_oldest_african_angolachelys_angola_turtle.pdfWebsite

A new Late Cretaceous turtle, Angolachelys mbaxi gen. et sp. nov., from the Turonian (90 Mya) of Angola, represents the oldest eucryptodire from Africa. Phylogenetic analysis recovers Angolachelys mbaxi as the sister taxon of Sandownia harrisi from the Aptian of Isle of Wight, England. An unnamed turtle from the Albian Glen Rose Formation of Texas (USA) and the Kimmeridgian turtle Solnhofia parsonsi (Germany), are successively more distant sister taxa. Bootstrap analysis suggests those four taxa together form a previously unrecognized monophyletic clade of marine turtles, herein named Angolachelonia clade nov., supported by the following synapomorphies: mandibular articulation of quadrate aligned with or posterior to the occiput, and basisphenoid not visible or visibility greatly reduced in ventral view. Basal eucryptodires and angolachelonians originated in the northern hemisphere, thus Angolachelys represents one of the first marine amniote lineages to have invaded the South Atlantic after separation of Africa and South America.

Vineyard, D. P., Jacobs L. L., Polcyn M. J., Mateus O., Schulp A. S., & Strganac C. (2009).  Euclastes from the Maastrichtian of Angola and the distribution of the Angolachelonia. Eugene Gaffney Turtle Symposium. , Royal Tyrrell Museum
Mateus, O., Jacobs L. L., Polcyn M. J., Schulp A. S., Neto A. B., & Antunes M. T. (2008).  Dinosaur and turtles from the Turonian of Iembe, Angola. Livro de Resumos de Tercer Congreso Latinoamericano de Paleontologia de Vertebrados. 156., Neuquén, Argentina Abstractmateus_et_al_2008_dinosaur_and_turtles_from_the_turonian_of_iembe_angola.pdf