Some Birds of Prey from the Upper Pliocene of Kansas
Some birds of prey from the Upper Pliocene of Kansas.---Although many arian fossils from the local faunas of the Rexroad formation (Upper Pliocene), Meade County, Kansas, have now been reported, several species of birds of prey remain. These fossils, which Dr. C. W. Hibbard of The University of Michigan Museum of Paleontology a.nd his field parties collected, come from the Rexroad and Fox Canyon local faunas of the Rexroad formation. These two localities arc described by Hibbard (1950). The two local faunas have been treated as one in the past, but Hibbard's (1967) latest view is that they arc distinct. The Fox Canyon local fauna is now considered to be older than the Rexroad and is distinct on the basis of its small mammals (Hibbard, 1967). Birds have bccn reported previously from these local faunas by Wetmore (1944), Tordoff (1951, 1959), Brodkorb (1964, 1967), Collins (1964), Ford (1966), Murray (1967), a.nd Fcduccia (1967, 1968). The birds of prey represented arc as follows: Accipiter sp.---Two distal ends of tibiotarsi represent an accipitcr approximately the size of the Recent A. cooperi, but the clements arc not sufficiently diagnostic to warrant the naming of a new species or the definite assignment of the fossils to the Recent form. One bone, a 42-mm piece of the distal end of a left tibiotarsus (UMMP No. V57506, from the Rexroad local fau.na, loc. no. 3) measures 10.8 mm in width through condyles. The same measurement for eight specimens of Recent A. cooperi females gives a mcan of 10.1 mm, with a range of 9.2-10.9 mm. The smaller fossil, a 17.1-mm piece of the distal end of a left tibiotarsus (UMMP No. V45422, from the Rexroad local fauna, loc. UM-K3-53) measures 9.0 mm in width through condyles. The same measurement for five males of Recent A. cooperi gives a mean of 8.5 mm, with a range of 8.3-8.8 mm. Whether or not both fossils represent females or one a female and the other a male cannot bc dctcrmi.ned, but it is probably best to assume that only one species is represented. Buteo sp.--A fragment of a right coracold (UMMP No. V24767, from the Fox Canyon local fauna, loc. UM-K1-47) represents a large species of Buteo close in size and morphology to B. jamaicensis, but it is too fragmentary to permit allocation. No useful measurements could be taken.
Fossil and Recent Avifaunas and the Interamerican Interchange
Ornithologists have long known that important interchanges took place in the Cenozoic between the North and South American avifaunas (von Ihering, 1927; Lonnberg, 1927). The debate about what taxa were involved and what direction they migrated has not often been resolved satisfactorily, however, because Recent birds give clues that can be interpreted in different ways by different people and because fossil birds have frequently been dismissed since they apparently offer such insignificant evidence.
Melanocins A, B and C, new melanin synthesis inhibitors produced by Eupenicillium shearii. I. Taxonomy, fermentation, isolation and biological properties.
New melanin synthesis inhibitors, melanocins A, B and C, were isolated from the fermentation broth and mycelium extract of Eupenicillium shearii F80695. Melanocin A, an isocyanide compound, inhibited mushroom tyrosinase and melanin biosynthesis of B16 melanoma cells with IC50 value of 9.0 nM and MIC value of 0.9 microM, respectively. Melanocin A also inhibited growth of Streptomyces bikiniensis. While, the structurally very related but non-isocyanide compounds melanocins B and C did not show inhibitory activity in these assays. Melanocins A, B and C showed potent antioxidant activity with scavenging activity of DPPH radical and superoxide anion radical.