The presence at Silveirinha of one of the earliest, ? Late Paleocene or Lowermost Eocene, european representatives of the genus Diplocynodon is based mostly on isolated bones and teeth (often from juveniles). This small-sized form is the only crocodilian so far recognized in this site. The longevity of Diplocynodon in Portugal becomes much extended; the genus survived there until the Middle Miocene at least. A discussion on the possible affinities with other eocene Díplocynodon and especially those from Cubillos-Valdegallina (Zamora, Spain) is presented. On the other hand, differences have been detected in comparison with: Díplocynodon tormis, from the middle Eocene of the Douro basin in Spain, which may belong to another phyletic line; and the aff. Diplocynodon from Dormaal (Belgium) and Le Quesnoy (France), nearly contemporaneous of Silveirinha. The Silveirinha Diplocynodon and many other data strongly suggest moist, subtropical, quite limited in space environments related to an alluvial plain crossed by small, meandering channels. 

In this article is described a new species of Nyctitheriidae with primitive characters: Leptacodon nascimentoi n. sp. from the early Eocene of Silveirinha (Portugal). 

Equus caballus antunesi, nova subspecies, was a hypsodont, slender, and rather small horse (around 141cm at the withers), with narrow hooves and protocones longer on P3/-P4/ than on M1/-M2/. It does not fit in any of the different "types" of Pleistocene caballine horses previously recognized but may be related to the horse from the Acheulean of Solana del Zamborino.
Hypsodonty, small size, slenderness, narrow hooves are all characters that can easily be related to ecological conditions. Equus caballus antunesi was probably a horse adapted to rather dry and cold conditions and to a hard ground. It does not seem related at all to the North-European Equus caballus germanicus-gallicus group. 

A new artiodactyl, Diacodexis antunesi n.sp., is described from the early Eocene of Silveirinha, Portugal. Comparisons are made with Diacodexis gazini GODINOT, 1978, D. varleti SUDRE et al., 1983, D. cf. varleti from Paris Basin sites, D. sp. from Dormaal and from localities in Spain and England, D. secans from North America and D. pakistanensis from Asia; affinities and evolutive tendencies are discussed. The presence of Diacodexis in the locality of Silveirinha confirms the very early Eocene age of the latter. As Diacodexis antunesi appears ta be more primitive than D. gazini from Rians (early Eocene of France), it lends corroboration to the interpretation (essentially based previously on condylarths) of the Silveirinha assemblage as the oldest Eocene fauna known in Europe and supports the hypothesis that early artiodactyls migrated from Europe to North America. 

The petrosal of the Paulchoffatiidae HAHN, 1969 is described and compared with that of younger multituberculates and of other Mesozoic mammals. The "Morrison petrosal", described by Prothero (1983), is also discussed; it probably belongs to the multituberculates. The reconstruction of the ventral side of the Paulchoffatiinae-skull, given by Hahn in 1987, is completed by addition of the otic and the occipital region. 

The ventral face of the Paulchoffatiinae skull (Multituberculata, Lower Kimmeridgian, Portugal) is new reconstructed. Some details hitherto unknown are added, as the presence of jugals, the structure of the palatine and the extension of the pterygoids. The situation of the m2/ is discussed. Kielanodon hopsoni n. g., n. sp. is erected, known by its upper p3-5/. From Guimarotodon leiriensis the mandible with its dentition is made known. New informations concerning the milk-dentition and the replacement of teeth are also added.