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Vertebrate Tracksites in the Middle Jurassic-Upper Cretaceous of South Tunisia
No full textFour vertebrate tracksites from the Middle Jurassic and
Upper Cretaceous in the Tataouine basin of southern Tunisia
are described. Approximately 130 tridactyl footprints distributed
over an area of 200 square meters, preserved on Callovian beds
exposed at the Beni Ghedir site, represent the oldest evidence of a
dinosaur fauna in Tunisia. In addition, three tracksites—Chenini,
Ksar Ayaat, and Jebel Boulouha—have been discovered in the
Cretaceous beds of the upper Continental Intercalaire, previously considered as a strictly marine depositional sequence. In addition
to dinosaur tracks, the Chenini tracksite (late Albian) includes
poorly preserved crocodilian tracks, and footprints assigned to a
pleurodiran turtle have been recovered at the Ksar Ayaat locality
(early Cenomanian). The Jebel Boulouha tracksite is dominated by
well-preserved tridactyl tracks referred to small-sized theropods.
Depositional settings of each tracksite have been defined on
stratigraphic and sedimentologic data, and tracks were ascribed to
different ichnocoenoses in relation to their paleoenvironments. This
new and differentiated track record gives important information
on how the fossil vertebrate fauna changed in southern Tunisia
during mid-Jurassic to mid-Cretaceous times. These data provide
a unique and useful census of tetrapod associations along the
southern margin of the peri-Mediterranean area
First record of bird tracks in the Late Cretaceous (Cenomanian) of Tunisia
No full textThe discovery of fossil bird tracks from the Cenomanian Kerker Member
(Zebbag Formation) in southern Tunisia represents the oldest report of
fossil birds from the Cretaceous of continental Africa. Three small bird
tracks were discovered in a track-bearing surface dominated by tridactyl
dinosaur footprints and are attributed to the ichnogenus Koreanaornis. This
represents the first occurrence of this ichnogenus in Africa and indicates a
worldwide distribution of these shorebirdlike tracks, previously known only
from Asia and North America. Tracks described in this study are also
smaller than any other fossil bird track known to date, thus they can be
included in the minute size class following modern bird track groups. A
comparison with present-day shorebird tracks indicates strong similarities
in size, morphology, and environment with extant members of the Actitis
genus, commonly known as sandpipers, which inhabit arid central African
tidal flats. The occurrence of bird tracks in the early Late Cretaceous of
Tunisia also brings important new insight into the paleoecology of an area
previously thought to be a site of exclusively marine deposition
The “Continental Intercalaire” of southern Tunisia: stratigraphy, paleontology, and paleoecology
No full textThe ‘‘Continental Intercalaire’’ deposits of southern Tunisia preserve one of the most diverse Early Cretaceous
vertebrate fauna from Africa, consisting of elasmobranchs, actinopterygians, sarcopterygians, turtles,
crocodyliforms, pterosaurs, and non-avian dinosaurs. Vertebrate remains representative of both
marine and fluvial environments have been historically referred to a specific bonebed within the Chenini
Member, which crops out extensively in the Tataouine region. A stratigraphic revision of the mainly siliciclastic
deposits of the Douiret and the Aïn El Guettar formations in the area based on new sedimentological
and paleontological data is presented. Data collected indicate the presence of multiple fossil-bearing
strata encompassing the stratigraphic interval from the Berriasian to the Albian and document faunal
variation through time as well as major environmental and climatic changes. Detailed sedimentological
analysis combined with biostratigraphic correlation performed at a basin scale indicate lateral facies variability
within each formation as a result of tectonically and climatically driven zonations within the
Tataouine Basin in the Early Cretaceous. Furthermore, proposed stratigraphic correlations indicate that
vertebrate remains previously referred to the fluvial Chenini Member (and in particular theropod and
sauropod dinosaurs) are instead representative of a transgressive deposit which mark the base of the
overlying Oum ed Diab Member
New data on two large dinosaur tracksites from the Middle Jurassic of Eastern Turkmenistan, Central Asia
No full textNew dinosaur-dominated tracksites in the Late Jurassic and Early Cretaceous of southern Tunisia
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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