Cranial morphology and systematics of an extraordinary sample of the Late Neogene dwarf tapir, Tapirus polkensis (Olsen)

2009 ◽  
Vol 83 (2) ◽  
pp. 238-262 ◽  
Author(s):  
Richard C. Hulbert ◽  
Steven C. Wallace ◽  
Walter E. Klippel ◽  
Paul W. Parmalee
Keyword(s):  
Single Species ◽  
Relative Strength ◽  
Cranial Morphology ◽  
Linear Measurements ◽  
Average Mass ◽  
Gray Fossil Site ◽  
Extant Species ◽  
Late Neogene ◽  
Fossil Site ◽  
Almost All

The previously poorly known “Tapiravus” polkensis Olsen, 1960 (Mammalia, Perissodactyla, Tapiridae) is now known from abundant, well preserved specimens from both the type area in central Florida and from the Gray Fossil Site (GFS) in eastern Tennessee. The latter has produced over 75 individuals, the greatest number of tapirids from a single fossil site, including many articulated skeletons. Almost all linear measurements taken on skulls, mandibles, and cheek teeth from GFS have coefficients of variation less than 10 (most between 3 and 7), indicating the presence of a single species. However, the sample reveals considerable intraspecific variation for a few key morphologic features, including development of the sagittal crest, outline shape of the nasals, and number and relative strength of lingual cusps on the P1. The Florida sample of T. polkensis is more limited, but has the same state as the GFS sample for all preserved characters of systematic significance, and while the Florida teeth are on average smaller (especially narrower lower cheek teeth), they fall either within or just below the observed range of the Gray Fossil Site population. The new material supports a reassignment of “Tapiravus” polkensis to the genus Tapirus, and demonstrates that the geologic age of the species is significantly younger than previously thought, Hemphillian rather than Barstovian. Tapirus polkensis is the smallest known North American Tapirus, and smaller than any of the extant species in the genus, with an estimated average mass of 125 kg.

Vitis seeds (Vitaceae) from the late Neogene Gray Fossil Site, northeastern Tennessee, U.S.A.

2010 ◽  
Vol 162 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Fade Gong ◽  
Istvan Karsai ◽  
Yu-Sheng (Christopher) Liu
Keyword(s):  
Gray Fossil Site ◽  
Late Neogene ◽  
Fossil Site

RECONSTRUCTING NUTRIENT HOTSPOTS IN TIME: INSIGHTS FROM THE GRAY FOSSIL SITE, TENNESSEE

2018 ◽  
Author(s):  
Sarah W. Keenan ◽  
◽  
Jennifer M. DeBruyn ◽  
Chris Widga
Keyword(s):  
Gray Fossil Site ◽  
Fossil Site ◽  
Nutrient Hotspots

scholarly journals Geographical matching of volatile signals and pollinator olfactory responses in a cycad brood-site mutualism

2015 ◽  
Vol 282 (1816) ◽  
pp. 20152053 ◽  
Author(s):  
Terence N. Suinyuy ◽  
John S. Donaldson ◽  
Steven D. Johnson
Keyword(s):  
Choice Experiments ◽  
Local Region ◽  
The Other ◽  
Beetle Species ◽  
Olfactory Preference ◽  
Olfactory Responses ◽  
Volatile Emissions ◽  
Extant Species ◽  
Insect Pollinators ◽  
Almost All

Brood-site mutualisms represent extreme levels of reciprocal specialization between plants and insect pollinators, raising questions about whether these mutualisms are mediated by volatile signals and whether these signals and insect responses to them covary geographically in a manner expected from coevolution. Cycads are an ancient plant lineage in which almost all extant species are pollinated through brood-site mutualisms with insects. We investigated whether volatile emissions and insect olfactory responses are matched across the distribution range of the African cycad Encephalartos villosus . This cycad species is pollinated by the same beetle species across its distribution, but cone volatile emissions are dominated by alkenes in northern populations, and by monoterpenes and a pyrazine compound in southern populations. In reciprocal choice experiments, insects chose the scent of cones from the local region over that of cones from the other region. Antennae of beetles from northern populations responded mainly to alkenes, while those of beetles from southern populations responded mainly to pyrazine. In bioassay experiments, beetles were most strongly attracted to alkenes in northern populations and to the pyrazine compound in southern populations. Geographical matching of cone volatiles and pollinator olfactory preference is consistent with coevolution in this specialized mutualism.

scholarly journals Ecological specialisation and evolutionary reticulation in extant Hyaenidae

2020 ◽  
Author(s):  
M V Westbury ◽  
Diana Le Duc ◽  
David A. Duchêne ◽  
Arunkumar Krishnan ◽  
Stefan Prost ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Single Species ◽  
Spotted Hyena ◽  
Genetic Changes ◽  
Slow Decline ◽  
Extant Species ◽  
Phylogenetic Discordance ◽  
Population Sizes ◽  
Olfactory Receptor Genes ◽  
Striped Hyena

AbstractDuring the Miocene, Hyaenidae was a highly diverse family of Carnivora that has since been severely reduced to four extant genera, each of which contains only a single species. These species include the bone-cracking spotted, striped, and brown hyenas, and the specialised insectivorous aardwolf. Previous genome studies have analysed the evolutionary histories of the spotted and brown hyenas, but little is known about the remaining two species. Moreover, the genomic underpinnings of scavenging and insectivory, defining traits of the extant species, remain elusive. To tackle these questions, we generated an aardwolf genome and analysed it together with those from the other three species. We provide new insights into the evolutionary relationships between the species, the genomic underpinnings of their scavenging and insectivorous lifestyles, and their respective genetic diversities and demographic histories. High levels of phylogenetic discordance within the family suggest gene flow between the aardwolf lineage and the ancestral brown/striped hyena lineage. Genes related to immunity and digestion in the bone-cracking hyenas and craniofacial development in the aardwolf showed the strongest signals of selection in their respective lineages, suggesting putative key adaptations to carrion or termite feeding. We also found a family-wide expansion in olfactory receptor genes suggesting that an acute sense of smell was a key early adaptation for the Hyaenidae family. Finally, we report very low levels of genetic diversity within the brown and striped hyenas despite no signs of inbreeding, which we putatively link to their similarly slow decline in Neover the last ∼2 million years. We found much higher levels of genetic diversity in both the spotted hyena and aardwolf and more stable population sizes through time. Taken together, these findings highlight how ecological specialisation can impact the evolutionary history, demographics, and adaptive genetic changes of a lineage.

scholarly journals Comparison of Prediction Equations for Estimating Inside Bark Diameters for Yellow-Poplar, Red Maple, and Red Pine in West Virginia

2009 ◽  
Vol 26 (1) ◽  
pp. 5-8 ◽  
Author(s):  
John R. Brooks ◽  
Lichun Jiang
Keyword(s):  
West Virginia ◽  
Single Species ◽  
Prediction Equation ◽  
Red Pine ◽  
Red Maple ◽  
Nonlinear Prediction ◽  
Prediction Equations ◽  
Yellow Poplar ◽  
Taper Function ◽  
Almost All

Abstract The ability to predict inside bark diameters was investigated using taper data for red maple, red pine and yellow-poplar from several stands in West Virginia. Inside bark estimates were based on Grosenbaugh's STX prediction equations, a segmented polynomial taper function fitted to inside bark diameter data, an existing polynomial prediction equation published for several hardwood species in this region and a nonlinear prediction equation fitted to the taper data. Grosenbaugh's STX is a computer program for processing tree measurements and includes three equations to allow flexibility and greater accuracy in predicting inside bark upper stem diameters. The nonlinear equation had the smallest overall prediction error in almost all cases investigated. The taper function had the largest error but does not require knowledge of the specific upper stem outside bark diameter. No single STX bark option was found to be optimal for all species or for a single species from two different geographic regions.

A new species of Chiridurothrips Okajima from Miocene amber of the Dominican Republic (Thysanoptera: Phlaeothripidae)

Zootaxa ◽  
2019 ◽  
Vol 4686 (1) ◽  
pp. 140-144
Author(s):  
MANFRED R. ULITZKA
Keyword(s):  
Abdominal Tergite ◽  
Compound Eyes ◽  
Ryukyu Islands ◽  
Alternative Possibility ◽  
Wing Vein ◽  
Extant Species ◽  
Basal Half ◽  
Campaniform Sensillum ◽  
Almost All ◽  
A New Species

The thysanopteran genus Chiridurothrips Okajima is known from a single extant species, C. hisakoae Okajima, collected in Japan (ThripsWiki 2019). Occurring on dead leaves and branches of evergreen trees in the subtropical Ryukyu Islands, this species remains known from only five females (Okajima 1981, 2006; also pers. comm. 2018). Within Phlaeothripidae, Chiridurothrips is associated with the tribe Plectrothripini. Species of this sub-group feed on fungal hyphae or the break-down products of fungal attack on decaying plant material (Mound & Ng 2018). They are found mainly under the bark of trees or on dead branches, and they do not seem to inhabit leaf-litter (Okajima 1981). At present, Plectrothripini comprises 60 extant species in 13 genera, with no fossils recorded. Of these species 32 are placed in the genus Plectrothrips Hood, ten in Streptothrips Priesner, and six in Chirothripoides Bagnall, whereas both Menothrips Hood and Mastigothrips Priesner each include only two species. The remaining eight species are all placed in separate monobasic genera (ThripsWiki 2019). Concerning this strongly asymmetric classification, Mound and Ng (2018) suggest that Plectrothripini might be particularly old, with the large number of monobasic genera each representing a relict lineage. An alternative possibility, however, might be an unusual instability in the genes controlling morphogenetic processes, and thus resulting in striking autapomorphies on which each one of these genera is diagnosed (Mound & Ng 2018). Species associated with Plectrothripini share the following character states (Okajima 1981; Mound & Tree 2017): antennae 8-segmented, segment II with the campaniform sensillum situated in the basal half, III–IV with stout sense cones, VIII slender with narrow base; head with posterior ocelli close to compound eyes; pronotum commonly with sclerotized plate eroded or reduced, prosternal basantra week or absent; legs with fore tarsal tooth large; mid and hind tibiae commonly with apical spur-like setae; macropterae with fore wings parallel-sided, usually with duplicated cilia; pelta broad at base, abdominal tergite II eroded laterally; abdominal sternites often with reticulate glandular areas. Regarding the fore wings, it seems worth mentioning that in some members of Plectrothripini the subbasal wing vein is reduced and thus the three subbasal wing setae are lacking (see Plectrothrips tenuis Okajima, Chiridurothrips [c.f. fig. 2], Chirothripoides, Lonchothrips Hood; Bhatti 1998; Okajima 1981). This short vein that is present in (almost all) other macropterous Phlaeothripidae has been interpreted as a plesiomorphic feature that resulted from the reduction of a former well-developed longitudinal first vein of ancestral Tubulifera, the Rohrthripidae (Ulitzka 2018, 2019). 

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