Enigmatic fossil plants with three-dimensional, arborescent-growth architecture from the earliest Carboniferous of New Brunswick, Canada.

The evolution of arborescence in Devonian plants, followed by their architectural radiation in the Carboniferous, is a transition fundamental to Earth-system processes and ecological development. However, this evolutionary transition in trees is based on preserved trunks, of which only a few known specimens possess crowns. We describe Mississippian-aged (Tournaisian) trees with a unique three-dimensional crown morphology from New Brunswick, Canada. The trees were preserved by earthquake-induced, catastrophic burial of lake-margin vegetation. The tree architecture consists of an unbranched, 16-cm-diameter trunk with compound leaves arranged in spirals of ∼13 and compressed into ∼14 cm of vertical trunk length. Compound leaves in the upper ∼0.75 m of the trunk measure >1.75 m in length and preserve alternately arranged secondary laterals beginning at 0.5 m from the trunk; the area below the trunk bears only persistent leaf bases. The principal specimen lacks either apical or basal sections, although an apex is preserved in another. Apically, the leaves become less relaxed toward horizontal and are borne straight at an acute angle at the crown. The compact leaf organization and leaf length created a crown volume of >20-30 m3. This growth strategy likely maximized light interception and reduced resource competition from groundcover. From their growth morphology, canopy size, and volume, we propose that these fossils represent the earliest evidence of arborescent subcanopy-tiering. Moreover, although systematically unresolved, this specimen shows that Early Carboniferous vegetation was more complex than realized, signaling that it was a time of experimental, possibly transitional and varied, growth architectures.

Colonial coral resilience by decreasing size: reaction to increased detrital influx during onset of the late Palaeozoic Ice Age.

Modern coral reefs and associated biodiversity are severely threatened by increasing terrestrial runoff. Similar scenarios could be suspected for geological times, but reef coral resilience is still an enigma. In late Visean-Serpukhovian (Mississippian foraminiferal zones/MFZ 14-16) times, a major glaciation phase of the late Palaeozoic Ice Age (LPIA) associated with enhanced terrestrial weathering and runoff coincides with a biodiversity crisis and coral reef decline. In this study, the impact of enhanced terrestrial runoff is tested on size variations of colonial corals Aulina rotiformis and Lithostrotion decipiens along a gradient of contemporaneous (Serpukhovian) open marine carbonate to near-shore siliciclastic facies in South China. Along this gradient, their sizes decrease from carbonate, through intermediate carbonate-siliciclastic, to siliciclastic facies. This is consistent with increasing abundance of terrestrial materials of high silicon, aluminium and phosphorus values. On a larger million-year-long interval (MFZ14-16) and for several palaeocontinents, size data of Lithostrotion decipiens and Siphonodendron pauciradiale show a distinct decline in late Visean, when enhanced terrestrial weathering occurred commonly with palaeosols developed during regression. This suggests that terrestrial sediment and nutrient input may have mainly controlled phenotypic plasticity in Mississippian reef corals, with a decrease in size as a component of resilience across the LPIA onset.

Abandonment of the Middle Cumberland Region of Tennessee during the Mississippian period: Temporal and sex differences in survivorship.

OBJECTIVES: The current research explores survivorship differences in the Middle Cumberland Region of Tennessee during the Mississippian period (ca. 1000-1500 AD). Using updated paleodemographic methods, this study investigates whether individuals from the Late Mississippian period had lower survivorship compared to individuals from the Early Mississippian period, foreshadowing groups on the brink of abandonment. Additionally, this study examines whether there were sex disparities in survivorship. MATERIALS AND METHODS: Adult age-at-death estimates from human skeletal remains (n = 545) were calculated using Transition Analysis, a Bayesian maximum likelihood method. Survivorship was reconstructed using Gompertz and Gompertz-Makeham hazards models, with Akaike Information Criterion compared to determine the best fitting model. RESULTS: For individuals surviving into adulthood, mean age-at-death decreased by 7 years from the Early Mississippian to Late Mississippian period. Marked differences between the sexes indicate lower survivorship of females compared to males. Male survivorship decreased sharply from the Early Mississippian to Late Mississippian period, from a mean age-at-death of 57.99 years to 44.45 years. Female survivorship remained constant throughout the Mississippian period (41 years). DISCUSSION: Temporal differences in male survivorship may be the result of interactions between climate change, decreased maize harvests, and sociopolitical strife. Sustained maternal mortality may have destabilized small-scale communities that characterized the Mississippian MCR, thereby precipitating population decline.

Rare pre-Columbian settlement on the Florida Gulf Coast revealed through high-resolution drone LiDAR.

Drone-mounted, high-resolution light detection and ranging reveals the architectural details of an ancient settlement on the Gulf Coast of Florida without parallel in the Southeastern United States. The Raleigh Island shell-ring complex (8LV293) of ca. 900 to 1200 CE consists of at least 37 residential spaces enclosed by ridges of oyster shell up to 4 m tall. Test excavations in 10 of these residential spaces yielded abundant evidence for the production of beads from the shells of marine gastropods. Beads and other objects made from gulf coastal shell were integral to the political economies of second-millennium CE chiefdoms across eastern North America. At places as distant from the coast as the lower Midwest, marine gastropods were imported in raw form and converted into beads and other objects by craftspeople at the behest of chiefs. Bead making at Raleigh Island is exceptional not only for its level of production at the supply end of regional demand but also for being outside the purview of chiefly control. Here we introduce the newly discovered above-ground architecture of Raleigh Island and outline its analytical value for investigating the organization of shell bead production in the context of ancient political economies. The details of shell-ring architecture achieved with drone-mounted LiDAR make it possible to compare the bead making of persons distributed across residential spaces with unprecedented resolution.

A new lower actinopterygian fish from the Upper Mississippian Bluefield Formation of West Virginia, USA.

The Upper Mississippian Bluefield Formation of the Mauch Chunk Group in southeastern West Virginia is known for its preservation of a variety of invertebrate taxa and early tetrapod trackways, but no lower actinopterygian remains have been formally described from these Carboniferous rocks. Here, the first lower actinopterygian fish is described from the Bluefield Formation of West Virginia. This fish is represented by a nearly complete articulated specimen with a three-dimensional snout and an unobstructed view of the gular and branchiostegal region. This new taxon is defined by a unique set of characters, which include features of the snout, circumorbital series, cheek, and operculo-gular region. These features make this fish different and distinct from previously described Carboniferous fishes. Some of the morphological features of note include the presence of a distinct lacrimal, premaxillary, ventral rostral and dorsal rostral bones, a narrow infraorbital ventral to the orbit, and a large crescent shaped infraorbital that contacts a single dermosphenotic. There is an anteriorly inclined hatchet-shaped preoperculum and six small suborbital bones anterior to the expanded region of this bone that filling the space between the preoperculum, dermosphenotic, and infraorbital. Posterior to the preoperculum, there is a single wedge-shaped dermohyal and a series of three rectangular anteopercular bones. The anteopercular bones extend halfway down the anterior border of the rectangular operculum. A median gular, two pairs of lateral gulars, and at least eight branchiostegal rays are present. The heterocercal caudal fin is deeply cleft and inequilobate. The scales have pectinated posterior margins and bear diagonal ridges of ganoine. The description of this new taxon represents the first actinopterygian and the first vertebrate body fossil described from the Bluefield Formation and the second actinopterygian taxon described from the Mauch Chunk Group in West Virginia.

A new cochliodont anterior tooth plate from the Mississippian of Alabama (USA) having implications for the origin of tooth plates from tooth files.

BACKGROUND: Paleozoic holocephalian tooth plates are rarely found articulated in their original positions. When they are found isolated, it is difficult to associate the small, anterior tooth plates with the larger, more posterior ones. Tooth plates are presumed to have evolved from fusion of tooth files. However, there is little fossil evidence for this hypothesis. RESULTS: We report a tooth plate having nearly perfect bilateral symmetry from the Mississippian (Chesterian Stage) Bangor Limestone of Franklin County, Alabama, USA. The high degree of symmetry suggests that it may have occupied a symphyseal or parasymphyseal position. The tooth plate resembles Deltodopsis? bialveatus St. John and Worthen, 1883, but differs in having a sharp ridge with multiple cusps arranged along the occlusal surface of the presumed labiolingual axis, rather than a relatively smooth occlusal surface. The multicusped shape is suggestive of a fused tooth file. The middle to latest Chesterian (Serpukhovian) age is determined by conodonts found in the same bed. CONCLUSION: The new tooth plate is interpreted as an anterior tooth plate of a chondrichthyan fish. It is referred to Arcuodus multicuspidatus Itano and Lambert, gen. et sp. nov. Deltodopsis? bialveatus is also referred to Arcuodus.

Mississippian subadults from the Middle Cumberland and Eastern regions of Tennessee: Biological indicators of population interaction.

OBJECTIVES: Human subadult skeletal remains can provide a unique perspective into biosocial aspects of Mississippian period population interactions within and between the Middle Cumberland (MCR) and Eastern Tennessee Regions (ETR). The majority of previous studies have concentrated on adult skeletal remains, leaving out a large and extremely important population segment. METHODS: Skeletal indicators of disease, growth, body proportions, and metabolic stress were collected from subadult remains from five archaeological sites over several temporal periods. Crucial to overcoming limitations associated with the osteological paradox, the biological results were placed into an archaeological context based on prior studies as well as paleoclimatological data. RESULTS: Results reveal homogeneity both within and between regions for most skeletal indicators. However, MCR individuals exhibit a higher frequency of pathology than those from ETC, while stature is significantly lower in younger subadults from the MCR. Within the ETR, there is no evidence for biological differences between Early Dallas and subsequent Late Dallas and Mouse Creek cultural phases. Despite presumed signs of increased conflict at the Dallas site, frequencies and types of skeletal pathology and growth disruptions are comparable to other regional sites. CONCLUSIONS: These findings suggest that despite cultural differences between the ETR and MCR, there was no large-scale intrusion from an outside population into the ETR during the Late Mississippian Period, or if one occurred, it is biologically invisible. Combined with climatic and archaeobotanical data, results suggest the MCR subadults were under increased stress in their earlier years. This may have been associated with increased interpersonal violence and dependence on few food sources occurring with greater scarcity.

Successful enrichment and recovery of whole mitochondrial genomes from ancient human dental calculus.

OBJECTIVES: Archaeological dental calculus is a rich source of host-associated biomolecules. Importantly, however, dental calculus is more accurately described as a calcified microbial biofilm than a host tissue. As such, concerns regarding destructive analysis of human remains may not apply as strongly to dental calculus, opening the possibility of obtaining human health and ancestry information from dental calculus in cases where destructive analysis of conventional skeletal remains is not permitted. Here we investigate the preservation of human mitochondrial DNA (mtDNA) in archaeological dental calculus and its potential for full mitochondrial genome (mitogenome) reconstruction in maternal lineage ancestry analysis. MATERIALS AND METHODS: Extracted DNA from six individuals at the 700-year-old Norris Farms #36 cemetery in Illinois was enriched for mtDNA using in-solution capture techniques, followed by Illumina high-throughput sequencing. RESULTS: Full mitogenomes (7-34×) were successfully reconstructed from dental calculus for all six individuals, including three individuals who had previously tested negative for DNA preservation in bone using conventional PCR techniques. Mitochondrial haplogroup assignments were consistent with previously published findings, and additional comparative analysis of paired dental calculus and dentine from two individuals yielded equivalent haplotype results. All dental calculus samples exhibited damage patterns consistent with ancient DNA, and mitochondrial sequences were estimated to be 92-100% endogenous. DNA polymerase choice was found to impact error rates in downstream sequence analysis, but these effects can be mitigated by greater sequencing depth. DISCUSSION: Dental calculus is a viable alternative source of human DNA that can be used to reconstruct full mitogenomes from archaeological remains. Am J Phys Anthropol 160:220-228, 2016. © 2016 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Linear enamel hypoplasia in Schroeder Mounds (11HE177): A Late Woodland period site in Illinois.

Adults and subadults recovered from the Late Woodland period (∼A.D. 800-1100) Schroeder Mounds site (11HE177) from west-central Illinois who preserve permanent incisors and/or canines (N=46) were examined for the presence of macroscopically visible linear enamel hypoplasia (LEH) by case, by tooth type, number of hypoplastic defects by tooth type, and estimated developmental age of occurrence. The raw case frequency of LEH (16/46) is 34.8 percent. The Schroeder Mounds subadults (N=15) have a higher case frequency (i.e., 60 percent versus 22.6 percent), number of stress episodes per tooth, and a longer developmental age range of hypoplastic defects than the adults. With no subsistence or settlement context, the Schroeder Mounds sample was compared to published (solely) adult LEH data from eight western Illinois sites segregable as either Middle (∼50 B.C.-A.D. 400) and Late Woodland period semi-sedentary forager-horticulturalists or Mississippian period (∼A.D. 1150-1250) sedentary (i.e., large aggregated village) maize-intensive agriculturalists. The adult Schroeder Mounds LEH patterns align with the Woodland samples with minor differences inclining the Schroeder sample toward a forager-farmer subsistence/settlement strategy. The Schroeder Mounds subadult patterns and prevalence may reflect factors that contributed toward their early death. Whether these factors can be framed by the subsistence/settlement system will require comparative data.

New dental and isotope evidence of biological distance and place of origin for mass burial groups at Cahokia's mound 72.

OBJECTIVES: Mound 72 at Cahokia figures prominently into interpretations of early Mississippian sociopolitical development. A previous study utilizing dental morphology concluded that the groups of mostly young adult females interred in four mass graves in Mound 72 were likely not from Cahokia and possibly reflect sacrificial offerings from outside communities. The purpose of this study is to reevaluate these findings using multiple indicators of biological relatedness and place of origin/migration. MATERIALS AND METHODS: Biological relatedness in Mound 72 was examined using dental metrics and morphology. Four additional archaeological samples from nearby sites were included to better assess biological variation within Mound 72. Strontium isotope analysis (87 Sr/86 Sr) was also conducted on individuals from several burial features in Mound 72 to determine heterogeneity in place of origin. RESULTS: Biodistance studies indicate that individuals in the four mass graves are phenotypically similar to other groups in the region, whereas F229-lower, a burial group with an aberrant mortuary context, is phenotypically distinct. Strontium isotope analyses show that mean Sr signatures for each feature investigated fall within the established local range for Cahokia. However, the range of Sr ratios for individuals in F229-lower is very narrow, suggesting they reflect a single population from a limited geologic region. DISCUSSION: Collectively, these results question the long-standing idea that individuals in the four mass graves were non-local to Cahokia and suggest that F229-lower contained a biologically dissimilar group that either came from an outside region with a similar Sr signature to Cahokia, or represent a distinct and restricted group from the region. Am J Phys Anthropol 158:341-357, 2015. © 2015 Wiley Periodicals, Inc.