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Bony-Tongue Fishes (Teleostei: Osteoglossomorpha) From The Eocene Nanjemoy Formation, Virginia, Eric J. Hilton, Jeffrey Carpenter Jan 2020

Bony-Tongue Fishes (Teleostei: Osteoglossomorpha) From The Eocene Nanjemoy Formation, Virginia, Eric J. Hilton, Jeffrey Carpenter

VIMS Articles

Bony-tongue fishes, Osteoglossomorpha, are distributed in North and South America, Africa, Asia, and Australia and are found on all continents except Antarctica in the fossil record. The group includes fishes such as the mooneyes (Hiodontidae), freshwater knifefishes (Notopteridae), elephantfishes (Mormyridae), and the arowanas and pirarucu (Osteoglossidae). Remains identified as belonging to the family Osteoglossidae are known from the Nanjemoy Formation of Maryland and northern Virginia and comprise isolated teeth and fragmentary jaw bones assigned to the now extinct †Brychaetus muelleri. The second author discovereda partial toothed parasphenoid among other isolated and frag-mentary vertebrate microfossils from the Fisher–Sullivan Site of ...


Species Boundaries, Specialization, And The Radiation Of Sponge-Dwelling Alpheid Shrimp, J Duffy Jan 1996

Species Boundaries, Specialization, And The Radiation Of Sponge-Dwelling Alpheid Shrimp, J Duffy

VIMS Articles

Microevolutionary studies and natural history suggest that host-specialization has promoted the high diversity of tropical sponge-dwelling snapping shrimps (Decapoda, Alpheidae, Synalpheus). Yet the taxonomic difficulty of this genus has precluded rigorous tests of this hypothesis. S. rathbunae Coutiere is among the most abundant invertebrates inhabiting the framework of sponges and dead coral that forms the floor of Caribbean coral reefs. Even within a small area S. rathbunae exhibits the apparently wide variation in size, color, and morphology that has long frustrated efforts to identify and define species boundaries within this large (> 100 described species) genus. Here I show that sympatric ...


Stratigraphic Consistency And The Shape Of Things, Me Siddall Jan 1996

Stratigraphic Consistency And The Shape Of Things, Me Siddall

VIMS Articles

Huelsenbeck (1994) identified three unsolved issues regarding the use of temporal information in the fossil record: (1) how goodness of fit between stratigraphy and phylogeny should be determined, (2) how the significance of this fit should be determined, and (3) how those results might be employed other than for description. With respect to goodness of fit, Huelsenbeck (1994) suggested that his stratigraphic consistency index (SCI) was both intuitively simple and not subject to the biases inherent in other stratigraphic indices. With respect to these prior indices (Gauthier et ai., 1988; Norell and Novacek, 1992), apparent biases are the result of ...


Phylogenetic Covariance Probability: Confidence And Historical Associations, Me Siddall Jan 1996

Phylogenetic Covariance Probability: Confidence And Historical Associations, Me Siddall

VIMS Articles

The correlation that exists among multiple cladograms is often taken as evidence of some underlying macroevolutionary phenomenon common to the histories of those clades and, thus, as an explanation of the patterns of association of the constituent taxa. Such studies have various forms, the most common of which are cladistic biogeography and host-parasite coevolution. The issue of confidence has periodically been a theoretical consideration of vicariance biogeographers but in practice has been largely ignored by others. Previous approaches to assessing confidence in historical associations are examined here in relation to the difference between simple-event and cumulative probabilities and in relation ...