The Cretaceous miospore Microreticulatisporites sacalii (Deák and Combaz) n. comb. occurs in the Dakota Formation of Iowa and the lower Tuscaloosa Group of Louisiana and Mississippi. These occurrences represent the first reported from North America. The presence of the species in mid-Cretaceous strata of North America is consistent with the upper Albian to Cenomanian interval from which it has been recorded in Europe. Review of the morphology of these spores and the systematics of the genus Vadaszisporites, to which the species originally was assigned, require transfer of the species and suppression of Vadaszisporites as a junior synonym of Microreticulatisporites Knox emend. Potonié and Kremp, 1954.

The type specimen of Megalodelphis magnidens Kellogg, 1944, from the Late Tertiary of Florida, is not a long-beaked dolphin of the mammalian order Cetacea as it was originally described. The presence of splenial and angular bones in the holotype mandible, along with a suture for the surangular bone and an external mandibular fenestra, are reptilian characters unknown in the Mammalia. Details of the morphology and placement of the teeth and the conformation of the mandible reveal that this specimen belongs to a crocodilian, and should be referred to the long-snouted estuarine crocodile, Gavialosuchus americanus. Therefore, Megalodelphis magnidens Kellogg, 1944, becomes a junior synonym of Gavialosuchus americanus (Sellards, 1915). The edentulous “rostral” (actually mandibular) fragment referred by Kellogg to M. magnidens does represent a large, long-beaked odontocete cetacean; however, its fragmentary condition does not permit a positive allocation to genus. Pending a revision of the long-beaked odontocetes, this specimen is regarded as Odontoceti incertae sedis.

Fossiliferous Late Silurian strata have not previously been recognized in the folded Appalachians south of central Virginia (Berry and Boucot, 1970). In this note, we report that the Red Mountain Formation at two localities in northern Alabama (Sparks Gap and Clear Branch Gap in Red Mountain near Birmingham, Figure 1) has yielded fossils like those of the Cobleskill Limestone (Pridolian, latest Late Silurian). The Red Mountain Formation in this area consists of interbedded sandstone, mudstone, claystone and limestone; some beds are hematitic and most are intensely weathered. The critical fossils are the brachiopod Eccentricosta sp. cf. E. jerseyensis (Weller, 1900) and the ostracode Welleriopsis? sp. aff. W.? pustulosa Berdan, 1972. The Eccentricosta beds at Sparks Gap and Clear Branch Gap are assigned to the Red Mountain because they are lithologically similar to lower beds in the formation. Thus the youngest part of the Red Mountain Formation in the Birmingham area is of Late Silurian, Pridolian, age. At Sparks Gap, underlying beds yielded Late Silurian corals that are not assigned to a faunal zone.

Radiolaria have been recovered in acid residues from late Middle Cambrian strata in western Utah. Although the first Cambrian radiolaria were described by Nazarov (1973) from the Batenevskij Mountains of eastern Kazakhstan in the Soviet Union, radiolaria have not been reported from the Cambrian of North America. Except for the Kazakhstan specimens, the oldest known radiolaria are from the Lower Ordovician of western Spitsbergen (Fortey and Holdsworth, 1971). In North America only two accounts of Ordovician assemblages have been reported from southwestern Newfoundland and eastern Nevada (Bergström, 1974; Dunham and Murphy, 1976).

Macropodoids from the Tarkarooloo local fauna, including Nambaroo tarrinyeri n. gen. and sp., N. saltavus n. sp., N. novus n. sp. and Palaeopotorous priscus n. gen. and sp., include the most plesiomorphic macropodids and potoroids known. Together with the newly discovered macropodoids from the Pinpa and Yanda local faunas they are also the oldest macropodoids described. Study of the morphology of these plesiomorphic macropodoids indicates that the trigonid of the M2 in potoroids and macropodids is composed of different structures (the protoconid and metaconid in macropodids and the protoconid and protostylid in potoroids). Also, the posterior cingulum in macropodids is a neomorphic structure, and not homologous with the posterior cingulum (the posthypocristid and postentocristid) in potoroids and phalangerids. A unique M2 trigonid configuration, where the cristid obliqua connects with the protostylid, is here recognized as being present in plesiomorphic macropodoids and phalangerids, and possibly represents a synapomorphy for a clade containing members of those groups.

Collins (1973), in a major systematic study of the Upper Cretaceous cirripeds of the eastern Gulf Coast, described four species of Cretiscalpellum, four of Arcoscalpellum, one of Virgiscalpellum (with two subspecies), and one of Brachylepas. In a companion paper, Mellen (1973) analyzed the stratigraphic and geographic distribution of these species and established the following biostratigraphic zones (Figure 1):

Presence of palynomorph assemblages that display exquisite preservation in evaporite deposits makes them invaluable as age indicators, as often no other fossils are present. However, such use of palynomorphs has been extremely limited because of complications in extraction from the surrounding rock material. Palynomorphs found in evaporites frequently cannot be removed by conventional uses of hydrofluoric and hydrochloric acids, or by modifications of these techniques (Sittler, 1955; Freudenthal, 1964; and Visscher, 1966), as neither acid is capable of removing significant quantities of sulfate minerals. Inadequate removal of these minerals prevents a good concentration of spores and pollen and hinders the preparation of useful microscope slide mounts.

Mineral separates of five tuffs interbedded in the mammal-bearing Huayquerías and Tunuyán formations in Mendoza Province, west-central Argentina, were dated by the 40K-40Ar method. At the locality of Rio Seco Ultima Aguada on the east side the Meseta Guadal three biotite concentrates of a tuff from a level that apparently corresponds to the very top of the Huayquerias Formation (or less probably to the very bottom of the Tunuyan Formation, sensu Dessanti, 1946) yielded an average age of 5.8 ± 0.1 Ma. The boundary between the Huayquerias Formation (namesake and type formation and fauna of the Huayquerian Land Mammal Age) and the Tunuyan Formation (which contains a Montehermosan age fauna at this locality) is thus about 5.8 Ma. At the locality of Rio Seco de la Salada on the west side of the Meseta Guadal, glass concentrates from two tuffs in the upper part of the Tunuyan Formation yielded ages of 2.6 ± 0.1 and 2.4 ± 0.3 Ma, respectively (the latter date is from a tuff located 90 m stratigraphically above the former). These dates indicate that the rocks and faunas from the upper part of the Tunuyan Formation are of Chapadmalalan (i.e., 2.8 to 2.5 Ma) and Uquian (i.e., 2.5 to 1.5 Ma) age. The faunas from the lower and middle parts of the Tunuyan Formation on the east side of the Meseta Guadal are apparently all of Montehermosan age (i.e., ca. 6.0 to 2.8 Ma).

The bivalve Odontogryphea thirsae, formerly “Ostrea thirsae,” is restricted to the Nanafalia Formation and is extensively used as a biostratigraphic zonal indicator in the Paleocene of the southeastern and central United States. Toulmin (1977) noted that O. thirsae was reported from the Tuscahoma Sand in early publications but stated (p. 191), “Reports of occurrence in the Tuscahoma Sand are probably in error.”