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Larry D. Martin is professor of ecology and evolutionary biology and curator of vertebrate paleontology at the University of Kansas. He is the author of some three hundred scientific papers [...]

A new genus and two new species of primitive, saltatorial, insectivorous mammals (Leptictida: Leptictidae) are described from the Lower Oligocene, Brule Formation, Nebraska. The new forms have narrower skulls with relatively longer snouts than Leptictis, to which all North American Oligocene species have been thought to belong.

Abstract: Dalingheornis liweiigen. et sp. nov., a new enantiornithine bird was collected from the early Cretaceous Yixian Formation in northeastern China. It is the first record of a highly specialized heterodactyl foot in Mesozoic birds. The Y‐shaped furcula with short hypocleidum is different from that of other enantiornithines. The minor metacarpal is robust and longer than the major metacarpal. A long bony tail composed of 20 caudal vertebrae with chevrons resembling those of dromaeosaurids and thus, highlighting again the evolutionary relationship between birds and non‐avian theropods. Well‐preserved alula feathers and a heterodactyl foot provide strong evidence for the arboreal habit of Dalingheornis.

The size, shape and position of the mouth and sensory features such as the nose, eyes and ears in the nimravid barbourofelins are reconstructed. The earliest barbourofelin studied, Sansanosmilus, is the most similar to both pantherine and nonpantherine felids in sensory structure morphology. Through time, the species of the barbourofelin lineage diverge from felids with regard to facial features. Evolutionary trends include expansion of the nasal region, a more lateral orientation of the eyes and lowered position for the ears. Increased width and shortening of the muzzle accommodates the large oral opening required by the large gape of Barbourofelis, culminating in B. frickiwith eyes oriented laterally enough to reduce stereoscopic vision. The ear position in this species is also significantly lower than in the earlier barbourofelins or felids. This may reflect an anatomic compromise between sensory structure position and changes in relative size, shape and position of other skull features. These changes correlate with increased canine tooth length and increased gape, exemplified byBarbourofelis fricki. Cranial soft tissue structures are restored through scars of attachment on the fossil bones, and the proportions of these features to one another determined. New observations provide criteria for reconstructing soft tissue anatomy in extinct animals.

Discusses paleopathology, which is the study of diseases found in ancient fossils and skeletons and on a group of Mesozoic reptiles known as mosasaurs. Reason the physiology and behavior of extinct animals represent one of the most challenging problems of paleontology; Information on the first known fossil of a mosasaur; Origin of the name of mosasaurs.

Insect trace fossils are a relatively new source of climatic and taphonomic data. Because insects often have narrowly defined ecological requirements during their life cycle, they can be an exceptional source of data on season of death, temperature and moisture. We have found this to be true for dermestid pupation chambers and give three examples from the late Pliocene of Idaho and middle-late Pleistocene of Kansas.

Die Arvicoliden-Gattung Mimomys ist ein wichtiges biostratigraphisches Leitfossil im eurasiatischen Plio-Pleistozän. Ihr Auftreten in Nordamerika wäre von großer Bedeutung. Aufgrund der Untersuchung der Schmelzstrukturen müssen jedoch alle Taxa aus Nordamerika, die bislang Mimomys zugeordnet wurden, in andere Gattungen gestellt werden, die sich unabhängig von der Mimomys-Linie entwickelt haben und auf die Prosomys (= Promimomys)-Radiation zurückgehen dürften. Daraus folgert, daß die Mimomys-Radiation Nordamerika nicht erreicht hat. Für "Mimomys" monohani Martin wird die neue Gattung Loupomys vorgeschlagen.

The oldest known feathers from the Late Jurassic are already modern in form and microscopic detail. Because these oldest examples are assignable to an extinct branch (Sauriurae) of the basal avian dichotomy, their features must have been established at a significantly earlier date. The skin of a wide variety of dinosaurs is now known and is unlikely to represent a predecessor to a feather bearing integument. Examples of feathered dinosaurs result from erroneous identification of internal structures as part of the skin covering, and from the confusion of flightless birds from the Early Cretaceous of China with dinosaurs.