Brian Kraatz

• PhD, University of California, Berkeley
• Professor (Associate) at Western University of Health Sciences

Biological variation is often considered in a scalable hierarchy, e.g., within the individual, within the populations, above the species level. Morphological integration, the concept of covariation among constituent parts of an organism, is also hierarchical; the degree to which these 'modules' covary is a matter of the scale of the study as well a...

Highly cursorial animals are specialised for fast, sustained running via specific morphological adaptations, notably including changes in limb segment length and mechanical advantage. Members of the order Lagomorpha (hares, rabbits and pikas) vary in cursorial ability; hares are generally highly cursorial, rabbits more frequently saltate, and pikas...

Studies on the evolution of brain size variation usually focus on large clades encompassing broad phylogenetic groups. This risks introducing ‘noise’ in the results, often obscuring effects that might be detected in less inclusive clades. Here, we focus on a sample of endocranial volumes (endocasts) of 18 species of rabbits and hares (Lagomorpha: L...

The story of the discovery of late Miocene fossils within the Baynunah geological formation in Abu Dhabi’s western Al Dhafra region concerns a host of international paleontologists, many of whom have contributed to this volume, as well as the backing of their related scientific institutions.

This monograph presents the results of over 10 years of paleontological and geological survey in the Baynunah Formation of the United Arab Emirates. Exposed widely in western Abu Dhabi Emirate, the Baynunah Formation and its fossils provide the only record of terrestrial environments and evolution in the Arabian Peninsula during the late Miocene ep...

In addition to skeletal remains that record the presence of a diverse vertebrate fauna, the Baynunah Formation also preserves fossil trackways. These are found on deflated surfaces of carbonateCarbonate-rich beds, mainly at sites located inland from the coast. FootprintsFootprint (track), like other trace fossils, may be difficult to assign to part...

Fluvial sediments of the middle Atbara River Valley, eastern Sudan, contain abundant vertebrate fossils and stone tools. Previous work described two sedimentary units, the Butana Bridge Synthem (BBS) and the Khashm El Girba Synthem (KGS), with three divisions each (BBS1-3 and KGS1-3, from bottom to top, respectively). ²³⁰Th/U dating on bivalve shel...

Fossil localities of the Baynunah Formation are here described, including previously known localities and those discovered by fieldwork since 2002. Site descriptions and coordinates are given, including updated coordinates for previously known localities. Many localities have been damaged or entirely lost to development activities.

The Baynunah Formation of western Abu Dhabi Emirate includes the only record of late Miocene fossil mammals from the Arabian Peninsula. This study reports on new fossil rodents, recording three species previously unknown from the fauna. The first fossil squirrel from the Baynunah Formation is described here, although the limited material makes a de...

Due to their global distribution, invasive history, and unique characteristics, European rabbits are recognizable almost anywhere on our planet. Although they are members of a much larger group of living and extinct mammals [Mammalia, Lagomorpha (rabbits, hares, and pikas)], the group is often characterized by several well-known genera (e.g., Oryct...

The story of the discovery of late Miocene fossils within the Baynunah geological formation in Abu Dhabi’s western Al Dhafra region concerns a host of international paleontologists, many of whom have contributed to this volume, as well as the backing of their related scientific institutions. In particular, the first study of the Baynunah owes a lot...

The Baynunah Formation of western Abu Dhabi Emirate includes the only record of late Miocene fossil mammals from the Arabian Peninsula. This study reports on new fossil rodents, recording three species previously unknown from the fauna. The first fossil squirrel from the Baynunah Formation is described here, although the limited material makes a de...

In addition to skeletal remains that record the presence of a diverse vertebrate fauna, the Baynunah Formation also preserves fossil trackways. These are found on deflated surfaces of carbonate-rich beds, mainly at sites located inland from the coast. Footprints, like other trace fossils, may be difficult to assign to particular species, but provid...

Fossil localities of the Baynunah Formation are here described, including previously known localities and those discovered by fieldwork since 2002. Site descriptions and coordinates are given, including updated coordinates for previously known localities. Many localities have been damaged or entirely lost to development activities.

The study of ontogeny in the fossil record is complicated by two main factors: growth series are not available for many taxa, and correctly assigning juveniles and adults to the same taxon is often difficult, especially where several related taxa coexisted. Ontogenetic change can also be revealed in single individuals whose morphology records chara...

The study of ontogeny in the fossil record is complicated by two main factors: growth series are not available for many taxa, and correctly assigning juveniles and adults to the same taxon is often difficult, especially where several related taxa coexisted. Ontogenetic change can also be revealed in single individuals whose morphology records chara...

The study of ontogeny in the fossil record is complicated by two main factors: growth series are not available for many taxa, and correctly assigning juveniles and adults to the same taxon is often difficult, especially where several related taxa coexisted. Ontogenetic change can also be revealed in single individuals whose morphology records chara...

The skull of leporids (rabbits and hares) is highly transformed, typified by pronounced arching of the dorsal skull and ventral flexion of the facial region (i.e., facial tilt). Previous studies show that locomotor behavior influences aspects of cranial shape in leporids, and here we use an extensive 3D geometric morphometrics dataset to further ex...

Raw coordinate data within morphologika files

The tempo-spatial development of the Cenozoic Asian aridification across the Eocene-Oligocene and its controlling factors are important scientific topics in Earth Sciences, which are pertinent to regional and global tectonic and climatic events. However, sedimentary rocks preserving the record of aridification during this time from central Asia (AC...

Plate tectonics and eustatic sea-level changes have fundamental effects on paleoenvironmental conditions and bio-ecological changes. The Paratethys Sea was a large marine seaway that connected the Mediterranean Neotethys Ocean with Central Asia during early Cenozoic time. Withdrawal of the Paratethys from central Asia impacted the distribution and...

The mammalian order Lagomorpha has been the subject of many morphometric studies aimed at understanding the relationship between form and function as it relates to locomotion, primarily in postcranial morphology. The leporid cranial skeleton, however, may also reveal information about their ecology, particularly locomotion and vision. Here we inves...

We describe a variant nerve in a human cadaver patient that parallels the course of the left recurrent laryngeal nerve (RLN). Like the normal left RLN, the variant nerve branches from the vagus nerve and wraps around the arch of the aorta, but it passes anterior and medial to the ligamentum arteriosum (= fetal ductus arteriosus) instead of behind i...

We describe a variant nerve in a human cadaver patient that parallels the course of the left recurrent laryngeal nerve (RLN). Like the normal left RLN, the variant nerve branches from the vagus nerve and wraps around the arch of the aorta, but it passes anterior and medial to the ligamentum arteriosum (= fetal ductus arteriosus) instead of behind i...

The mammalian order Lagomorpha has been the subject of many morphometric studies aimed at understanding the relationship between form and function as it relates to locomotion, primarily in postcranial morphology. The leporid cranial skeleton, however, may also reveal information about their ecology, particularly locomotion and vision. Here we inves...

The mammalian order Lagomorpha has been the subject of many morphometric studies aimed at understanding the relationship between form and function as it relates to locomotion, primarily in postcranial morphology. The leporid cranial skeleton, however, may also reveal information about their ecology, particularly locomotion and vision. Here we inves...

1. Although Lagomorpha (rabbits, hares and pikas) have a long evolutionary history in Eurasia and Africa, including primitive genera of Eurasia historically considered assignable at the family level to Leporidae, the predecessors of modern rabbits were absent throughout this vast region for most of the Miocene until late in that epoch. During the e...

Tree-building with diverse data maximizes explanatory power. Application of molecular clock models to ancient speciation events risks a bias against detection of fast radiations subsequent to the Cretaceous-Paleogene (K-Pg) event. Contrary to Springer et al., post–K-Pg placental diversification does not require “virus-like” substitution rates. Even...

Strict consensus trees that a exclude Lavocatomys, b exclude Gaudeamus and c include both Gaudeamus and Lavocatomys

Cane rats (Thryonomyidae) are represented today by two species inhabiting sub-Saharan Africa. Their fossil record is predominately African, but includes several Miocene species from Arabia and continental Asia that represent dispersal events from Africa. For example, Paraulacodus indicus, known from the Miocene of Pakistan, is closely related to li...

To discover interordinal relationships of living and fossil placental mammals and the time of origin of placentals relative to the Cretaceous-Paleogene (K-Pg) boundary, we scored 4541 phenomic characters de novo for 86 fossil and living species. Combining these data with molecular sequences, we obtained a phylogenetic tree that, when calibrated wit...

Many living vertebrates exhibit complex social structures, evidence for the antiquity of which is limited to rare and exceptional fossil finds. Living elephants possess a characteristic social structure that is sex-segregated and multi-tiered, centred around a matriarchal family and solitary or loosely associated groups of adult males. Although the...

Despite significant recent improvements to our understanding of the early evolution of the Order Proboscidea (elephants and their extinct relatives), geographic sampling of the group's Paleogene fossil record remains strongly biased, with the first ~30 million years of proboscidean evolution documented solely in near-coastal deposits of northern Af...

Evidence for social behavior, group size and structure in the fossil record is generally limited to rare and exceptional fossil finds. Living elephants are an example of a group that exhibits complex and well-studied social behavior. Despite a rich proboscidean fossil record going back to the early Eocene, evidence on the antiquity of characteristi...

The cusp homology of Lagomorpha has long been problematic largely because their teeth are highly derived relative to their more typically tribosphenic ancestors. Within this context, the lagomorph central cusp has been particularly difficult to homologize with other tribosphenic cusps; authors have previously considered it the paracone, protocone,...

The Eocene-Oligocene boundary (EOB) marks a period of dramatic global climatic change correlated with pronounced mammalian faunal change. The timing of these events is well constrained in North America and Europe, but the Asian record has yet to produce a synthetic section linking environmental change, mammalian fossils, and precise geochronologica...

Dental and postcranial specimens of Gomphos shevyrevae, sp. nov., from the lower part of the Irdin Manha Formation at the Huheboerhe locality, Erlian Basin, Nei Mongol (Inner Mongolia), are described. The new species differs from G. elkema and G. ellae in having more robust teeth with inflated cusps and stronger lophs and a calcaneus with extra art...

Mimotonids have recently been recognized as the likely ancestors to Lagomorpha (rabbits, hares, and pikas). Here a new species of mimotonid, Gomphos ellae, from Tsagaan Khutel locality, Valley of Lakes, Mongolia is described. This new material shows typical mimotonid features while also exhibiting important derived lagomorph features and helps to b...

The Miocene Mammal Mapping Project (MIOMAP), a relational database of all published mammalian vertebrate localities between 30 and 5 million years old from the western United States, is now online for use by the paleontological community. The database is housed at the University of California at Berkeley, served through the Berkeley Natural History...

The paleontological record of mammals offers many examples of evolutionary change, which are well documented at many levels of the biological hierarchy—at the level of species (and above), populations, morphology, and, in ideal cases, even genes. The evolutionary changes developed against a backdrop of climatic change that took place on different s...

Fossil ratite eggshell fragments recovered from the Late Miocene Baynunah For-mation, United Arab Emirates, are described as Diamantornis laini and as an aepyorni-thid-type eggshell fragment. D. laini has been previously reported from the Late Miocene of Namibia and Kenya, whereas aepyornithid-type eggshell is known from many Neogene deposits in Eu...

Few researchers have attempted rigorous cladistic analyses of fossil ochotonids (pikas), largely due to the paucity and morphological conservativism of the fossils. However, pikas were diverse and widespread during the Cenozoic, and we therefore explore the applicability of cladistic analysis utilizing dental characters, which comprise most of thei...

The eastern border of the Hanna Basin, Wyoming, is defined by Simpson Ridge anticline, a Laramide structure that separates the Hanna Basin from the more easterly Carbon Basin. New geologic mapping along with interpretation of well logs and seismic-reflection data suggest that this structural feature was created through a combination of thick- and t...