The first definitive Middle Jurassic atoposaurid (Crocodylomorpha, Neosuchia), and a discussion on the genus Theriosuchus

Atoposaurids were a clade of semiaquatic crocodyliforms known from the Late Jurassic to the latest Cretaceous. Tentative remains from Europe, Morocco, and Madagascar may extend their range into the Middle Jurassic. Here we report the first unambiguous Middle Jurassic (late Bajocian–Bathonian) atoposaurid: an anterior dentary from the Isle of Skye, Scotland, UK. A comprehensive review of atoposaurid specimens demonstrates that this dentary can be referred to Theriosuchus based on several derived characters, and differs from the five previously recognized species within this genus. Despite several diagnostic features, we conservatively refer it to Theriosuchus sp., pending the discovery of more complete material. As the oldest known definitively diagnostic atoposaurid, this discovery indicates that the oldest members of this group were small-bodied, had heterodont dentition, and were most likely widespread components of European faunas. Our review of mandibular and dental features in atoposaurids not only allows us to present a revised diagnosis of Theriosuchus, but also reveals a great amount of variability within this genus, and indicates that there are currently five valid species that can be differentiated by unique combinations of dental characteristics. This variability can be included in future broad-scale cladistics analyses of atoposaurids and closely related crocodyliforms, which promise to help untangle the complicated taxonomy and evolutionary history of Atoposauridae

Further towards unambiguous edge bundling: Investigating power-confluent drawings for network visualization

Bach et al. [1] recently presented an algorithm for constructing confluent drawings, by leveraging power graph decomposition to generate an auxiliary routing graph. We identify two problems with their method and offer a single solution to solve both. We also classify the exact type of confluent drawings that the algorithm can produce as 'power-confluent', and prove that it is a subclass of the previously studied 'strict confluent' drawing. A description and source code of our implementation is also provided, which additionally includes an improved method for power graph construction

The Widths of Strict Outerconfluent Graphs

Strict outerconfluent drawing is a style of graph drawing in which vertices are drawn on the boundary of a disk, adjacencies are indicated by the existence of smooth curves through a system of tracks within the disk, and no two adjacent vertices are connected by more than one of these smooth tracks. We investigate graph width parameters on the graphs that have drawings in this style. We prove that the clique-width of these graphs is unbounded, but their twin-width is bounded.Comment: 15 pages, 2 figure

Edge-Path Bundling: A Less Ambiguous Edge Bundling Approach

Edge bundling techniques cluster edges with similar attributes (i.e. similarity in direction and proximity) together to reduce the visual clutter. All edge bundling techniques to date implicitly or explicitly cluster groups of individual edges, or parts of them, together based on these attributes. These clusters can result in ambiguous connections that do not exist in the data. Confluent drawings of networks do not have these ambiguities, but require the layout to be computed as part of the bundling process. We devise a new bundling method, Edge-Path bundling, to simplify edge clutter while greatly reducing ambiguities compared to previous bundling techniques. Edge-Path bundling takes a layout as input and clusters each edge along a weighted, shortest path to limit its deviation from a straight line. Edge-Path bundling does not incur independent edge ambiguities typically seen in all edge bundling methods, and the level of bundling can be tuned through shortest path distances, Euclidean distances, and combinations of the two. Also, directed edge bundling naturally emerges from the model. Through metric evaluations, we demonstrate the advantages of Edge-Path bundling over other techniques

Planar and Poly-Arc Lombardi Drawings

In Lombardi drawings of graphs, edges are represented as circular arcs, and the edges incident on vertices have perfect angular resolution. However, not every graph has a Lombardi drawing, and not every planar graph has a planar Lombardi drawing. We introduce k-Lombardi drawings, in which each edge may be drawn with k circular arcs, noting that every graph has a smooth 2-Lombardi drawing. We show that every planar graph has a smooth planar 3-Lombardi drawing and further investigate topics connecting planarity and Lombardi drawings.Comment: Expanded version of paper appearing in the 19th International Symposium on Graph Drawing (GD 2011). 16 pages, 8 figure

Scalability considerations for multivariate graph visualization

Real-world, multivariate datasets are frequently too large to show in their entirety on a visual display. Still, there are many techniques we can employ to show useful partial views-sufficient to support incremental exploration of large graph datasets. In this chapter, we first explore the cognitive and architectural limitations which restrict the amount of visual bandwidth available to multivariate graph visualization approaches. These limitations afford several design approaches, which we systematically explore. Finally, we survey systems and studies that exhibit these design strategies to mitigate these perceptual and architectural limitations

The New World species of Ataenius Harold, 1867 : 5. Revision of the A. strigatus group (Scarabaeidae: Aphodiinae: Eupariini)

The strigatus group of the New World species of Ataenius Harold is revised. Seventeen species are recognized including two species described as new: Ataenius ecruensis sp. nov. from the United States and A. oaxacaensis sp. nov. from Mexico. Fifteen previously used names are considered valid, three new synonyms are proposed: A. liogaster Bates (= A. edwardsi Chapin syn. nov. = A. hoguei Cartwright and Spangler syn. nov.), A. wenzelii Horn (= A. rudellus Fall, syn. nov.). New state records are presented for A. spretulus (Haldeman) (Washington) and A. cognatus (LeConte) (Indiana, Missouri, and Mississippi). The taxa are diagnosed, keyed and illustrated; available biological information and distribution data are given

Digenetic trematodes and cestodes from fishes of the San Joaquin delta

To date there has been only on major study concerned with parasites of freshwater fishes of California. E. C. Haderlie (1953) summarized investigations up to that year and conducted a general survey of the monogenetic and digenetic trematodes, cestodes, nematodes, acanthocephalans, copepods, and hirudinians of fishes of Northern California. From 2010 fishes representing 36 species of 11 families examined over a three-year period, he obtained a total of 59 species of helminth parasites, copepods, and hirudinians, which include 20 species of digenea and 16 species of cestodes. In addition to the taxonomic study, Haderlie attempted to correlate the relative occurrence of the parasites with various ecological habitats. These data are incomplete, except for a general ecological discussion of the parasites taken from Clear Lake and its contributing streams. In the Sacramento-San Joaquin area the monogenetic trematodes are the only group that has been extensively studied. This work has been done by Dr. J. D. Mizelle of Sacramento State College. The primary purpose of the current investigation is to gain some knowledge of the species of endoparasites of fishes of the San Joaquin Delta. Two hundred and thirty sic fish were examined, including diadromous, potamodramous, anandromous, and territorial species of San Joaquin Delta. This has resulted in the recovery of two previously described and one new adult digenea, three metacercariae, two adult and three larval cestodes,and two cestodarians. Not included in this study are the Acanthocephala and Nematoda. A few cestodes are also not included because of their poor condition. The Host-Parasite List (p. 49) of this paper gives a summary of the fishes examined by Haderlie (H) and the present author (E) with the number of each species examined and the species of trematodes and cestodes recovered