Gary D. Richards

Brief communication: Prehistoric dentistry in the American Southwest: A drilled canine from Sky Aerie, Colorado

A prehistoric Native American mandible from a Fremont site (circa AD 1025) in Colorado has a conical pit in the worn occlusal surface of the lower right canine. Natural causes for this modification are ruled out by the presence of internal striae, a finding confirmed by experimental replication. The canine was artificially drilled before the individuals death and is associated with a periapical abscess. This is one of a very few examples of prehistoric dentistry in the world, and the first from the American Southwest.

Foramen Magnum Ontogeny in Homo sapiens: A Functional Matrix Perspective

Historically, the foramen magnum (FM) has been an integral component of studies on skull ontogeny and evolutionary transformations of cranial form. Although this foramen has been considered a single entity, we hypothesize that it comprises two functional matrices, a ventral matrix and a dorsal matrix. In general, the ventral matrix is related to locomotor functions, whereas the dorsal matrix is related to neurological functions and fluid flow dynamics. To test our hypothesis, we used a large ontogenetic sample of modern human crania (seventh fetal month to adult) to (1) delineate bony size and shape ontogeny for both the foramen and its dorsal and ventral units; (2) delineate the role of synchondroses in the observed growth patterns and rates; and (3) explore the relationship between FM and cranial size, shape, and growth. Detailed growth patterns and rates are established for the bony FM and its ventral and dorsal skeletal units. These data are supplemented by literature and observational data on embryonic and fetal FM ontogeny, soft tissue relationships, anomalous/pathological extremes of size, and craniocervical anatomy and locomotor functions. The hypothesis that the FM is composed of a ventral and a dorsal functional matrix is supported by observed ontogenetic differences between ventral and dorsal skeletal units, as well as by the soft tissue anatomy of these matrices. Further documentation of these matrices has the potential to significantly enhance our understanding of the ontogenetic and evolutionary transformations of skull base morphology. Anat Rec, 2011.

Missing Omo L338y‐6 occipital‐marginal sinus drainage pattern: Ground sectioning, computer tomography scanning, and the original fossil fail to show it

The Omo L338y‐6 occipital region has been recently studied by White and Falk ( 1999 ), who claim that it shows a readily identifiable enlarged left occipital‐marginal sinus (O/M). These observations are contrary to the direct observations of previous investigators (Rak and Howell, 1978 ; Kimbel, 1984 ; Holloway, 1981 ; Holloway, 1988 ). White and Falk ( 1999 ) further argue that the presence of this enlarged O/M strongly suggests that the Omo L338y‐6 hominid was indeed a “robust” Australopithecus. We used direct sectioning and CT scanning to analyze magnified sections of a high‐quality first‐generation cast of the newly cleaned original fossil. These methods fail to show any evidence of a morphological landmark that can be interpreted as an enlarged O/M, either as an eminence or a sulcus. In contrast, the same techniques used with both SK 1585 and OH5 (“robust” Australopithecus with an enlarged O/M) show extremely visible and palpable enlarged O/Ms. Examination of the original Omo fossil confirms that it lacks an O/M. This evidence clearly shows that an enlarged O/M cannot be identified on either the original fossil or a first‐generation cast, although this does not rule out the possibility that the Omo L338y‐6 hominid was a “robust” Australopithecus. We believe that the differences between observers regarding this feature are most probably due to displacement caused by a crack and the different source materials employed, i.e., the difference between a first‐generation cast of the original fossil and a third‐ or fourth‐generation cast of the endocast made two decades ago. Anat Rec 266:249–257, 2002.

A new species of antilocapra from the late Quaternary of California

Abstract Late Quaternary antilocaprid material recovered recently from the San Joaquim River delta near Antioch,California represents a new species of Antilocapra . The new species id distinguised by aspects of horn core, orbit and temporal-fossa morphology which differ significantly from that of a large sample of A. americana and Pleistocene specimens referred to cf. A. americana . The new species also diverges markedly from a demonstrated allometric relationship between cranial size and horn-core size in A. americana . Based on the observed differences we assign these recently recovered specimens to Antilocapra pacifica nov, sp.

Erratum: Missing Omo L338y-6 occipital-marginal sinus drainage pattern: Ground sectioning, computer tomography scanning, and the original fossil fail to show it (Anatomical Record (2002) 266 (249-257))

Holloway RL, Yuan MS, Broadfield DC, Degusta D, Richards GD, Silvers A, Shapiro JS, and White TD. Missing Omo L338y-6 occipital-marginal sinus drainage pattern: ground sectioning, computer tomography scanning, and the original fossil fail to show it. Anat Rec 2002:266:249 257.