N. Adam Smith

Clemson University | CU · Campbell Geology Museum

Just as skeletal characteristics provide clues regarding behavior of extinct vertebrates, phylogenetically-informed evaluation of endocranial morphology facilitates comparisons among extinct taxa and extant taxa with known behavioral characteristics. Previous research has established that endocranial morphology varies across Aves; however, variatio...

Puffins, auks and their allies in the wing-propelled diving seabird clade Pan-Alcidae (Charadriiformes) have been proposed to be key pelagic indicators of faunal shifts in Northern Hemisphere oceans. However, most previous phylogenetic analyses of the clade have focused only on the 23 extant alcid species. Here we undertake a combined phylogenetic...

Hypotheses regarding the evolution of many clades are often generated in the absence of data from the fossil record and potential biases introduced by exclusion of paleontological data are frequently ignored. With regard to body size evolution, extinct taxa are frequently excluded because of the lack of body mass estimates—making identification of...

The last half century of paleornithological research has transformed the way that biologists perceive the evolutionary history of birds. This transformation has been driven, since 1969, by a series of exciting fossil discoveries combined with intense scientific debate over how best to interpret these discoveries. Ideally, as evidence accrues and re...

Of the more than 6,000 members of the most speciose avian clade, Passeriformes (perching birds), only the five species of dippers (Cinclidae, Cinclus) use their wings to swim underwater. Among nonpasserine wing‐propelled divers (alcids, diving petrels, penguins, and plotopterids), convergent evolution of morphological characteristics related to thi...

The appearance of a real-world feather is the result of light interactions with complex, patterned structures of varying scale; however, these have not yet been modeled for accurate rendering of feathers in computer graphics. Previously published works related to production and research have presented simplified curve models to represent the appear...

Relative brain size has long been considered a reflection of cognitive capacities and has played a fundamental role in developing core theories in the life sciences. Yet, the notion that relative brain size validly represents selection on brain size relies on the untested assumptions that brain-body allometry is restrained to a stable scaling relat...

The nearly complete skull of a raven (Aves, Corvidae) is reported from middle Pleistocene sediments (∼450–580 ka) of Jinyuan Cave near the city of Dalian on the Liaodong Peninsula of Liaoning Province, China. The new fossil closely resembles that of the Common Raven (Corvus corax), a species with a Holarctic extant distribution. It is one of the re...

The relatively extensive fossil record of owls (Aves, Strigiformes) in North America and Europe stands in stark contrast to the paucity of fossil strigiformes from Africa. The first occurrence of a fossil owl from the Paleogene of Africa extends the fossil record of this clade on that continent by as much as 25 million years, and confirms the prese...

Relative brain sizes in birds can rival those of primates, but large-scale patterns and drivers of avian brain evolution remain elusive. Here, we explore the evolution of the fundamental brain-body scaling relationship across the origin and evolution of birds. Using a comprehensive dataset sampling> 2,000 modern birds, fossil birds, and theropod di...

An extensive fauna of at least 77 taxa is reported from the basal Wilson Grove Formation in a small quarry just north of the town of Bloomfield, Sonoma County, California. The fauna represents intertidal to shallow subtidal water depths and water temperatures interpreted from the fauna, consistent with the latitude of the fossil locality (37° north...

Zygodactylidae are an extinct lineage of perching birds characterized by distinct morphologies of the foot and wing elements. Although the clade has a complex taxonomic history, current hypotheses place Zygodactylidae as the sister taxon to Passeriformes (i.e., songbirds). Given the rather sparse fossil record of early passeriforms, the description...

Morphological Character Scorings.

Fossils of pelagornithids (bony-toothed birds) have been reported from strata of Paleocene to Pliocene age, and from every continent. The extreme fragility of pelagornithid bones has no doubt contributed to their geographically and temporally sporadic record, and thus it has been difficult to appreciate any long-term phylogenetic trends through geo...

A relatively diverse assemblage of at least 17 vertebrates (three species of sharks, three genera of teleost fishes, nine marine mammals, and at least two species of bird) is reported from the basal Wilson Grove Formation in a small quarry just north of the town of Bloomfield in Sonoma County, California. The vertebrate, as well as associated inver...

The rapidly expanding interest in, and availability of, digital tomography data to visualize casts of the vertebrate endocranial cavity housing the brain (endocasts) presents new opportunities and challenges to the field of comparative neuroanatomy. The opportunities are many, ranging from the relatively rapid acquisition of data to the unprecedent...

Fossils provide the principal basis for temporal calibrations, which are critical to the accuracy of divergence dating analyses. Translating fossil data into minimum and maximum bounds for calibrations is the most important, and often least appreciated, step of divergence dating. Properly justified calibrations require the synthesis of phylogenetic...

Birds are maniraptoran theropod dinosaurs. The evidence supporting the systematic position of Avialae as a derived clade within Dinosauria is voluminous and derived from multiple independent lines of evidence. In contrast, a paucity of selectively chosen data weakly support, at best, alternative proposals regarding the origin of birds and feathers....

The Charadriiformes (shorebirds and allies) are an ecologically and morphologi- cally diverse clade with a global geographic distribution. The perceived antiquity of this lineage and the cryptic plumage and morphology of some charadriiforms have made them a frequent focus of study by ornithologists. Likewise, with the relatively recent advent of mo...

The Ameghinornithidae are an enigmatic group of potentially flightless Paleogene birds currently known from three European species. Herein, we report a new fossil that represents the first record of an ameghinornithid-like bird from Africa. The new speci- men was collected from the early Oligocene Jebel Qatrani Formation exposed in the Fayum Depres...

Although studies of osteological morphology, gross myology, myological histology, neuroanatomy, and wing-scaling have all documented anatomical modifications associated with wing-propelled diving, the osteohistological study of this highly derived method of locomotion has been limited to penguins. Herein we present the first osteohistological study...

Avian remains from the Early Miocene (~17 Ma) Moghra Formation of Egypt include new records of ‘waterbirds’ (storks, herons, pelicans and allies) and a ratite. Only a single avian fossil has been previously reported from Wadi Moghra and, thus, additional knowledge of the avifauna complements previously documented faunal and floral assemblages and p...

Misinterpretations of entropy and conflation with additional misunderstandings of the second law of thermodynamics are ubiquitous among scientists and non-scientists alike and have been used by creationists as the basis of unfounded arguments against evolutionary theory. Entropy is not disorder or chaos or complexity or progress towards those state...

Newly discovered fossil remains of an auk (Aves, Charadriiformes) extend the temporal range of Pan-Alcidae in the northeastern Atlantic Ocean basin and the geographic range of the clade during the Miocene. The new specimen consists of a partial ulna and a radius of a single individual. It represents the earliest fossil auk from the northeastern Atl...

A fossil from the Middle Miocene Rosarito Beach Formation of Baja California represents a previously undescribed, auklet-sized species of wing-propelled diving Pan-Alcidae (Ayes, Charadriiformes). This new taxon, Divisukus demerei, is recognized from the presence of a bifurcated scapulotricipital sulcus of the distal end of the humerus, a potential...

The auklets Aethia and Ptychoramphus comprise the smallest known Alcidae (Aves, Charadriiformes) and have a fossil record that extends into the Miocene. The evolution of auklets is poorly understood because systematic hypotheses of relationships among extant auklets are largely incongruent, the morphology of auklet fossils has not been evaluated in...

Alca (Aves, Alcidae) has a comparatively rich fossil record with respect to other charadriiformes, consisting of thousands of specimens. despite the abundance of fossil material, species richness in this clade has remained poorly understood, primarily because of the paucity of associated specimens. To address this issue, a combined morphometric and...

Fossils of pelagornithids (bony-toothed birds) have been reported from strata of Paleocene to Pliocene age, and from every continent. The extreme fragility of pelagornithid bones has no doubt contributed to their geographically and temporally sporadic record, and thus it has been difficult to appreciate any long-term phylogenetic trends through geo...

Although flightless alcids from the Miocene and Pliocene of the eastern Pacific Ocean have been known for over 100 years, there is no detailed evaluation of diversity and systematic placement of these taxa. This is the first combined analysis of morphological and molecular data to include all extant alcids, the recently extinct Great Auk Pinguinus...

We report a nearly complete skeleton of a new species of stem roller (Aves, Coracii) from the early Eocene Green River Formation of North America. The new species is most closely related to two species-depauperate lineages, Coraciidae (rollers) and Brachypteraciidae (ground rollers), that form a monophyletic crown clade (Coracioidea) with an exclus...