HGL50 is a latest Early-early Middle Eocene vertebrate-bearing locality located in Western Algeria. It has produced the richest and most diverse fauna of amphibians and squamate reptiles reported from the Palaeogene of Africa. Moreover, it is one of the rare faunas including amphibians and squamates known from the period of isolation of Africa. The assemblage comprises 17 to 20 taxa (one gymnophionan, one probable caudate, three to six anurans, seven ‘lizards’, and five snakes). Two new taxa were recovered: the anuran Rocekophryne ornata gen. et sp. nov. and the snake Afrotortrix draaensis gen. et sp. nov. The locality has also yielded the first confirmed anilioid snake, the first Palaeogene gymnophionan, and probably the first caudate from the Palaeogene (and possibly from the Tertiary) of Africa. The presence of a caudate at that time in Africa would be of particular interest; unfortunately, the available material does not permit a definitive identification. The fauna comprises Gondwanan and more specifically West Gondwanan vicariants, probably autochthonous groups and a Eurasian immigrant (assuming that the identification of the caudate is accurate). The fauna from HGL50 is clearly distinguished from the few other Eocene assemblages of Africa. However, if this results largely from differences in geological ages, geographic positions of the localities and mainly differences in environments took a part in the composition of the faunas. 

We report the discovery of amniotic eggshells and theropod teeth from the Late Cretaccous  period in Morocco.The megaloolithid family represents the only known dinosaur egg remains in the north part of Africa and attests indirectly to the occurrence of sauropod dinosaurs (titanosaurids) in the Maastrichtian of Africa.

  

A new hypothesis for the phylogenetic relationships of recent anomalurids and graphiurids is proposed, based on information from evolutionary lineages of Paleogene European rodents, particularly Gliridae, and Eocene Algerian Zegdoumyidae. Differences in first occurrences, in paleogeography, and in infraorbital structure in glirids (protrogomorphy and pseudomyomorphy) and graphiurids (hystricomorphy) separate Graphiuridae from Gliridae (Graphiurinae is here raised to family rank). Similar considerations, and dental morphology, suggest that Anomaluridae (appearing in the late Eocene) and Graphiuridae (appearing in the Pliocene) are related to early Eocene Zegdoumyidae. 

This paper is about the oldest African rodents faunas, from the late Early Eocene, or early Middle Eocene, Glib Zegdou (Algeria) and Chambi (Tunisia) localities. Five species are described and figured, belonging to a new family here created, the Zegdoumyidae.

This family is compared to the Early and Middle Eocene rodents families from Asia, Europe and North America (Chapattimyidae, Yuomyidae, Gliridae, Theridomyidae, lschyromyidae and Sciuravidae), as well as to those known from the Late Eocene African locality Bir El Ater (Anomaluridae and Phiomyidae).

On the one hand, it seems clear that the African endemic Anomaluridae arise from the Zegdoumyidae. On the other hand, the lschyromyidae, or primitive Sciuravidae, may be the most reliable ancestral groups for the Zegdoumyidae. Thus, this new family can be considered as the sister group for the American Sciuravidae on the one hand, and for the European Gliridae on the other hand.

The biogeographical consequences of these phylogenetic hypotheses are discussed. A new phase of communication between Europe and North Africa is inferred, during the Early Eocene. It has been followed by a short period of endemism, allowing the adaptive radiation for the Zegdoumyidae, preceding the immigration of the Phiomyidae, during the Late Eocene, probably from Asian relatives. 

Enamel microstructure in the incisors of Old- and New World hystricognath rodents:

The incisor enamel microstructure in more than 100 genera of fossil and Recent hystricognath and sciurognath rodents was studied. A multiserial schmelzmuster is present in the Hystricognathi, the Ctenodactylidae, advanced Chapattimyidae, and in Pedetes. A redefinition of pauciserial and multiserial HSB is given that makes the two enamel types unambiguously distinguishable which apparently represent well defined evolutionary levels. In the pauciserial Schmelzmuster the IPM is thicker than in the multiserial one. In pauciserial HSB the IPM always surrounds each prism, and the crystallites of the IPM run parallel to prism direction; transition zones between HSB are lacking; the inclination of the HSB is normally very low and the prism cross sections are not flattened but somewhat irregular. The number of prisms per HSB is no good distinctive character for pauciserial and multiserial HSB, since there exists a wide overlap. The pauciserial schmelzmuster is primitive, the multiseiial derived because: 1. the pauciseiial schmelzmuster appears earlier in the fossil record in the most primitive rodents (Paramyids s.l. and Ctenodactyloids); 2. the Eocene Ctenodactyloidea show pauciserial HSB but the Oligocene and younger ones are characterized by multiserial HSB; 3. in the outgroup comparison, the Eurymylidae (Mixodontia) show pauciserial HSB; 4. biomechanically, multiserial HSB strenghten the enamel better than pauciserial HSB, since their IPM runs nearly always in an angle of 45° or more to the prisms.

In multiseríal HSB three subtypes can be distinguished which are differentiated by the IPM orientation. Primitive is a (rarely strict) parallel or acute angular, anastomozing IPM, and derived is an interrow sheet-like ("plattenartige") IPM. This evolutionary polarity is indicated by enamel evolution in the Ctenodactylidae which show an acute angular IPM in the Oligocene and a rectangular interrow sheet-like IPM since the Miocene. Among the Caviomorpha a rectangular interrow sheet-like IPM is restricted to the Octodontoidea; therefore they must be considered derived in terms of their enamel structure. The first multiserial HSB in rodent incisors appear in phiomyids or chapatrimyids from the Upper Eocene of Algeria. The IPM is acute angular and anastomozing. The worldwide next younger multiserial HSB are found in Lower Oligocene phiomyids of Fayum, Egypt There already a rectangular interrow sheet like IPM is present (in Metaphiomys) besides the acute angular anastomozing IPM.

The first Caviomorpha from the Deseadan (Oligocene-Miocene) likewise show already acute angular anastomozing IPM (e.g. Scozamys) and rectangular interrow sheet-like IPM (Platypittamys). Therefore the first Caviomorpha cannot be positioned close to a transition from pauciserial to multiserial HSB. In none of the potential caviomorph ancestors from southern North America multiserial HSB or transitional stage between pauciserial and multiserial HSB could be found. The similarities between the enamel types of the Fayum rodents and the rodents from the Deseadan of South America make a derivation of the Caviomorpha from Paleogene North African phiomorph rodents or their direct ancestors most probable. This supports at the same time a descent of the platyrrhine Primates from North African anthropoids.
  

Remarkable association of a small infraorbital foramen, similar to that in recent Heterocephalus, and of a strong muscular print on the dorsal anterior part of the zygomatic plate and on the premaxillary. Several anatomical structures to be compared with those of Heterocephalus suggest relationships with this genus. Richardus supports the ancestrality of the hystricomorph character in the bathyergids