Steven Heritage

University of Southern California | USC · Department of Integrative Anatomical Sciences

Molecular phylogenetic studies that have included sirenians from the genera Trichechus, Dugong, and Hydrodamalis have resolved their interrelationships but have yielded divergence age estimates that are problematically discordant. The ages of these lineage splits have profound implications for how to interpret the sirenian fossil record — including...

Aim: Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroeco...

A phylogenetic framework provides the necessary evolutionary context for studies of comparative anatomy, life history, behavior, biogeography, systematics, and conservation. Time-scaled phylogenetic analyses require researchers to include calibration ages which are used to fit a model that transforms tree branch lengths into units of time. The incl...

Diverse lines of geological and geochemical evidence indicate that the Eocene-Oligocene transition (EOT) marked the onset of a global cooling phase, rapid growth of the Antarctic ice sheet, and a worldwide drop in sea level. Paleontologists have established that shifts in mammalian community structure in Europe and Asia were broadly coincident with...

Ancestral state reconstruction (ASR) is a critical tool in comparative biology. Given a phylogenetic tree and observed trait states for taxa at the tree's tips, ASR aims to model ancestral trait states at the tree's internal nodes. Thus, the pattern, tempo, and frequency of a character's evolution can be considered in a phylogenetic framework. Soft...

The Somali Sengi or Somali Elephant-shrew ('Elephantulus' revoilii, Macroscelidea, Mammalia) has been considered a "lost species" and is primarily known from about 39 museum specimens, with no new vouchered occurrence records since the early 1970s. The scientific literature contains no data concerning living Somali Sengi individuals and the species...

Subfossil tenrec specimens in the Duke Lemur Center natural history collections are from sites across Madagascar including Anjohibe Cave and others in the Northwest, The Cave of the Lone Barefoot Stranger (at Ankarana) and others in the North, and Ankilitelo Cave and others in the Southwest. Analyses of the microfossil record at Ankilitelo (~500 ye...

In 1967 G.G. Simpson described three partial mandibles from early Miocene deposits in Kenya that he interpreted as belonging to a new strepsirrhine primate, Propotto. This interpretation was quickly challenged, with the assertion that Propotto was not a primate, but rather a pteropodid fruit bat. The latter interpretation has not been questioned fo...

Family Macroscelididae (Sengis). Family text includes sections covering: systematics; morphology; habitat; general habits; communication; diet & feeding; breeding; locomotion, home range, & social organization; conservation. With 32 photographs. --- Species accounts address the 20 extant species and include: distribution maps; taxonomy; descriptive...

The ''scaly-tailed squirrels'' of the rodent family Anomaluridae have a long evolutionary history in Africa, and are now represented by two gliding genera (Anomalurus and Idiurus) and a rare and obscure genus (Zenkerella) that has never been observed alive by mammalogists. Zenkerella shows no anatomical adaptations for gliding, but has traditionall...

Over the course of the last four decades, regular expeditions to the Fayum Depression of northern Egypt led by Elwyn Simons resulted in the recovery of a large and important sample of early fossil primates that are now held in the collections of the Egyptian Geological Museum and the Duke Lemur Center Division of Fossil Primates. Many of these foss...

Adaptive characterizations of primates have usually included a reduction in olfactory sensitivity. However, this inference of derivation and directionality assumes an ancestral state of olfaction, usually by comparison to a group of extant non-primate mammals. Thus, the accuracy of the inference depends on the assumed ancestral state. Here I presen...