Tooth characters of protohippine horses with special reference to species from the Merychippus zone, California

The critical review of equine tooth characters attempted in this paper is the result of a study of the protohippine horses obtained from the Merychippus Zone of the north Coalinga district, California. During the conduct of extensive excavations in this zone since 1928 by the California Institute, more than two thousand teeth of the genus Merychippus have been collected. In addition to the types represented by the equine material, a number of associated land mammals have been secured. The faunal list, which includes some fifteen species, suggests that this locality occupies a stratigraphic position approximately late middle Miocene in age. The variation displayed in the dental characters of the merychippine material from the Merychippus Zone necessitated comparisons with cheek-teeth of Equidae from practically all of the Miocene formations furnishing vertebrate remains in the Pacific Coast and Great Basin Provinces. A comprehensive study of these collections clearly demonstrates that many of the cheek-tooth characters employed in the description of type specimens of fossil horses are variable to an extent which renders them unreliable in a determination of species. The variation of these characters within a large collection also indicates that it is possible for teeth referable to a particular species to have a wider stratigraphic range than has been hitherto appreciated. The conclusion is reached that the presence of a species has less value in reaching an age determination of the strata in which it occurs than evidence furnished by an association of several species

Anchitheriine Horses from the Merychippus Zone of the North Coalinga District, California

Excavations by the California Institute of Technology in the Merychippus zone of the North Coalinga district, California, have added considerably to our knowledge of the Equidae from this horizon. In addition to a large amount of material representing the genus Merychippus, the teeth of three genera of anchitheriine horses have been found. These teeth are of value in that they furnish additional information regarding the taxonomic position and geographic distribution of several of the middle Tertiary genera known from the Pacific Coast and Great Basin provinces

Tooth characters of protohippine horses with special reference to species from the Merychippus zone, California

The critical review of equine tooth characters attempted in this paper is the result of a study of the protohippine horses obtained from the Merychippus Zone of the north Coalinga district, California. During the conduct of extensive excavations in this zone since 1928 by the California Institute, more than two thousand teeth of the genus Merychippus have been collected. In addition to the types represented by the equine material, a number of associated land mammals have been secured. The faunal list, which includes some fifteen species, suggests that this locality occupies a stratigraphic position approximately late middle Miocene in age. The variation displayed in the dental characters of the merychippine material from the Merychippus Zone necessitated comparisons with cheek-teeth of Equidae from practically all of the Miocene formations furnishing vertebrate remains in the Pacific Coast and Great Basin Provinces. A comprehensive study of these collections clearly demonstrates that many of the cheek-tooth characters employed in the description of type specimens of fossil horses are variable to an extent which renders them unreliable in a determination of species. The variation of these characters within a large collection also indicates that it is possible for teeth referable to a particular species to have a wider stratigraphic range than has been hitherto appreciated. The conclusion is reached that the presence of a species has less value in reaching an age determination of the strata in which it occurs than evidence furnished by an association of several species

The fauna of the Merychippus zone, north Coalinga District, California

The fauna from the Merychippus zone, north of Coalinga, California, was first described by J. C. Merriam in 1915. The assemblage\ud as listed by Merriam included four genera of land mammals, namely, Merychippus, Proethennops, Procamelus and Telrabelodon. As recognized by Dr. Merriam, the discovery of mammalian remains in the marginal marine series of California possesses particular significance in that it furnishes an important aid in determining the time relationships between the marginal marine deposits of the Pacific Coast and the continental formations of the Great Basin and Great Plains areas of North America. The present studies were initiated, therefore, with a view to enlarging the fauna from this horizon and to establishing more accurately the time relationships of the assemblage. Moreover, it seemed desirable to record information concerning the mode of accumulation of the fossiliferous deposits and of the ecologic conditions under which the fauna existed

Growth Performance of Tetrapleura Tetraptera (Schum and Thonn) Seedlings to Green Manure and Inorganic Fertilizer

The use, types and method of fertilizers for agricultural and forest plants should be sustainable, ecofriendly and natural to the environment. Application of green manure is being used nowadays for soil nutrient management, growth and plant yields because of their natural effects. This study investigated the use of green manure andinorganicfertilizer on the growth performance of Tetrapleura tetraptera. Topsoil, leucaenana leucoephala (leave powder) and inorganic fertilizer (NPK 15: 15:15) were used. The fertilizer were weighed and applied to the 5kg of soils at 0g, 10g and 20g each and were replicated six times. Growth parameters such as seedling heights, number of leaf and stem diameter were assessed weekly for aperiod of three months. The application leucaenana leucoephala’s leave powder as green manure showed significantly high effects on the growth parametersof Tetrapleura tetraptera seedlings at p ≤ 0.05. This study has shown the efficacy of leucaenana leucoephala’s leave powder as green manure for optimum growth of Tetrapleura tetraptera seedlings

The Atacama Cosmology Telescope: Dynamical Masses and Scaling Relations for a Sample of Massive Sunyaev-Zel'dovich Effect Selected Galaxy Clusters

We present the first dynamical mass estimates and scaling relations for a sample of Sunyaev-Zel'dovich effect (SZE) selected galaxy clusters. The sample consists of 16 massive clusters detected with the Atacama Cosmology Telescope (ACT) over a 455 sq. deg. area of the southern sky. Deep multi-object spectroscopic observations were taken to secure intermediate-resolution (R~700-800) spectra and redshifts for ~60 member galaxies on average per cluster. The dynamical masses M_200c of the clusters have been calculated using simulation-based scaling relations between velocity dispersion and mass. The sample has a median redshift z=0.50 and a median mass M_200c~12e14 Msun/h70 with a lower limit M_200c~6e14 Msun/h70, consistent with the expectations for the ACT southern sky survey. These masses are compared to the ACT SZE properties of the sample, specifically, the match-filtered central SZE amplitude y, the central Compton parameter y0, and the integrated Compton signal Y_200c, which we use to derive SZE-Mass scaling relations. All SZE estimators correlate with dynamical mass with low intrinsic scatter (<~20%), in agreement with numerical simulations. We explore the effects of various systematic effects on these scaling relations, including the correlation between observables and the influence of dynamically disturbed clusters. Using the 3-dimensional information available, we divide the sample into relaxed and disturbed clusters and find that ~50% of the clusters are disturbed. There are hints that disturbed systems might bias the scaling relations but given the current sample sizes these differences are not significant; further studies including more clusters are required to assess the impact of these clusters on the scaling relations.Comment: 15 pages, 4 figures. Accepted for publication in The Astrophysical Journal; matches published version. Full Table 8 with complete spectroscopic member sample available in machine-readable form in the journal site and upon request to C. Sif\'o