Print ISSN: 0031-0247
Online ISSN: 2274-0333
Frequency: biannual
A new stem hystricognathous rodent from the Eocene of Tunisia
Palaeotis weigelti restudied
Paleocene Palaeocarcharodon from Maryland
New Gargantuavis specimens from the Late Cretaceous of France
Macroscelidea, Insectivora and Chiroptera from the Miocene of east Africa
Eocene (57) , Quercy phosphorites (37) , Systematics (32) , Rodents (29) , Mammalia (26)
Un nouveau genre de ?Palaeotheriidae (Perissodactyla, Mammalia) décelé dans les phosphorites du Quercy (Eocène supérieur ou Oligocène) d'après un arrière crâne sans dents.Jean-Albert RemyKeywords: endocranial cast; Epitympanic sinus; Palaeotheriidae; Paleogene; Quercy phosphorites; skull anatomyAbstract A rear skull from the Quercy Phosphorites is described. It documents a new perissodactyl genus, likely assignable to the family Palaeotheriidae and probably paleogene of age. Owing to the lack of any tooth, this family assignment remains however somewhat hypothetical. The specimen is firstly characterised by the presence of a wide epitympanic sinus swelling and hollowing the squamosal shell and the post-glenoid process. This cavity might make up a peculiar pattern of improvement for the hearing apparatus by carrying out a kind of drum near the middle ear, whereas the bony tympanic remains barely bulged and forms but a few developed auditory bulla. This pattern appears an outcome of a trend observed with many palaeotheriids, such as Plagiolophus. Furthermore, the endocranial cast shows a rather high degree of gyrencephaly for a paleogene mammal. The prominent lambdoidal crest points out a powerful nape musculature and a lowered head bearing. Consequently, it is assumed that such an animal was probably living in somewhat open places, at the expense of rather tough vegetables. It might have been accordingly provided with a semi-hypsodont, cement covered, "plagiolophoid" dentition. Article infos Published in Vol. 28, Fasc. 1 (1999) |
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The endocranial cast and encephalization quotient of Ptilodus (Multituberculata, Mammalia)David W. Krause and Zofia Kielan-JaworowskaKeywords: encephaIization quotient; endocranial cast; Montana; Multituberculata; olfactory bulbs; Paleocene; PtilodusAbstract Simpson (1937a) reconstructed the brain of the Paleocene multituberculate Ptilodus as having the olfactory bulbs widest anteriorly, an unusual condition among mammals. Slight preparation and reexamination of the endocast specimens of Ptilodus reveals that the olfactory bulbs in fact taper anteriorly, as in the recently-described endocranial casts of three multituberculate species from the Late Cretaceous of Asia, and as in those of other mammals. The brain of Ptilodus was therefore essentially of the same general pattem as in other multituberculates. Ptilodus differs, however, in having the vermis more deeply inserted between the cerebral hemispheres. Other details concerning the endocast morphology of Ptilodus are clarified. Article infos Published in Vol. 22, Fasc. 2-3 (1993) |
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Multituberculate endocranial castsZofia Kielan-JaworowskaKeywords: Allotheria; Cretaceous; endocranial cast; Mongolia; multituberculatesAbstract A reconstruction of a multituberculate endocranial cast is made on the basis of a complete natural cast prepared from the skull of Chulsanbaatar vulgaris, and other less complete endocasts, all from the Late Cretaceous of Mongolia. The multituberculate endocast is of mammalian pattern but it has retained a therapsid-like lateral profile with a deep rhombencephalon and a shallow telencephalon. It is characterized by: a heart-shaped cross-section of the telencephalon; an extensive lissencephalic neocortex; a very prominent pons placed far anteriorly; a lack of cerebellar hemispheres, and very large paraflocculi. Its structure, very different from the brains of other mammals, suggests thats the Multituberculata branched very early from the main mammalian stock. This supports Simpson's (1945) idea that the Multituberculata should be placed in a subclass of their own: Allotheria MARSH. The endocast and braincase structure show that the Multituberculata had strongly developed senses of smell and hearing. The encephalization quotient of approx. 0.55 evaluated for Ch. vulgaris is relatively high for a Mesozoic mammal. Article infos Published in Vol. 13, Fasc. 1-2 (1983) |
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Etude paléoneurologique comparative de Parabos Cordieri (De Christol), un bovidae (Mammalia, Artiodactyla) du Pliocène d'Europe Occidentale.Catherine GromolardKeywords: Bovidae; endocranial cast; Europe; PlioceneAbstract A skull of Parabos cordieri, undamaged by fossilisation, allows us to make an endocranial cast, which is compared to those of Bos taurus, Boselaphus tragocamelus and Hippotragus equinus. These are studied by general form (shape, volume, « rolling-up›› and inclination), and by detailed morphology (gyri and sulci patterns, rete mirabile, importance of rhinencephalon and cerebellum). Article infos Published in Vol. 12, Fasc. 2 (1982) |
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