News Article | January 24, 2017
Wolf-sized giant otters that weighed more than 100 pounds lived among birds and water lilies in prehistoric China more than 6 million years ago. Otter evolution is not well understood as fossils of the creature are rare and scattered worldwide. The discovery of an ancient species of a large otter in China, though, offers researchers some insights about these animals. In 2010, researchers discovered a well-preserved cranium of the now-extinct species of giant otter dubbed Siamogale melilutra in an open lignite mine in Yunnan province in China. The fossils also include various teeth, limb bones, and lower jaw of the creature. Denise Su, from the Cleveland Museum of Natural History, and colleagues who published their findings in the Journal of Systematic Paleontology on Jan. 22, described the prehistoric creature to be up to three times larger than any modern otter. Su said that the fossilized cranium was almost complete albeit flattened to about an inch and a half thick. Because the bones are fragile, researchers were not able to reconstruct them physically. Su and colleagues decided to take CT scans of the cranium to digitally reconstruct it. The cranium revealed that the creature had teeth with badger features and provided the researchers with crucial information on how otters evolved. The cranium also shed light on a dental mystery. Scientists wanted to know whether different species of otter inherited their teeth from a common ancestor or the teeth evolved separately since they were eating similar things, a process called convergent evolution. By comparing the specimen of the prehistoric otter to modern and other fossil otters, the researchers found that the otters' bunodont teeth emerged because of convergent evolution and not because of inheritance from a common ancestor. The ancient creature also featured strong jaws that may have been used for crunching hard objects, possibly freshwater mollusks and large shellfish. "I think it used its powerful jaws to crush hard clams for food, somewhat like modern sea otters, although the latter use stone tools to smash shells," said Xiaoming Wang, from the Natural History Museum of Los Angeles County. Wang said that if the creature was not smart enough to use tools, then the only option it likely had was to develop more powerful jaws by increasing its body size. Despite its large size, the S. melilutra is not the largest otter that researchers have so far discovered. Fossils of a larger ancient otter have previously been found in Africa. The biggest living otter is the South American giant river otter, which weighs up to 70 pounds. Otters belong to a family of mammals that include the badger, marten, mink, and the weasel. Researchers said that studying the newly found prehistoric species of otter will provide them with new insights on how otters evolved. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | January 11, 2017
Famous footprints of nearly 3.7-million-year-old hominids, found in 1976 at Tanzania’s Laetoli site, now have sizable new neighbors. While excavating small pits in 2015 to evaluate the impact of a proposed field museum at Laetoli, researchers uncovered comparably ancient hominid footprints about 150 meters from the original discoveries. The new finds reveal a vast range of body sizes for ancient members of the human evolutionary family, reports an international team led by archaeologists Fidelis Masao and Elgidius Ichumbaki, both of the University of Dar es Salaam in Tanzania. A description of the new Laetoli footprints appears online December 14 in eLife. Scientists exposed 14 hominid footprints, made by two individuals as they walked across wet volcanic ash. More than 500 footprints of ancient horses, rhinos, birds and other animals dotted the area around the hominid tracks. Like previously unearthed tracks of three individuals who apparently strode across the same layer of soft ash at the same time, the latest footprints were probably made by members of Australopithecus afarensis, the team says. Best known for Lucy, a partial skeleton discovered in Ethiopia in 1974, A. afarensis inhabited East Africa from around 4 million to 3 million years ago. All but one of the 14 hominid impressions come from the same individual. Based on footprint dimensions, the researchers estimate that this presumed adult male — nicknamed Chewie in honor of the outsized Star Wars character Chewbacca — stood about 5 feet 5 inches tall and weighed nearly 100 pounds. That makes him the tallest known A. afarensis. The team calculates that the remaining hominid footprint was probably made by a 4-foot-9-inch female who weighed roughly 87 pounds. Stature estimates based on the other three Laetoli footprint tracks fall below that of the ancient female. Lucy lived later than the Laetoli crowd, around 3.2 million years ago, and was about 3 ½ feet tall. If Laetoli’s five impression-makers were traveling together, “we can suppose that the Laetoli social group was similar to that of modern gorillas, with one large male and a harem of smaller females and perhaps juveniles,” says paleontologist and study coauthor Marco Cherin of the University of Perugia in Italy. Chewie’s stature challenges a popular assumption that hominid body sizes abruptly increased with the emergence of the Homo genus, probably shortly after A. afarensis died out, Cherin adds. The new paper presents reasonable stature estimates based on the Laetoli footprints, but “we don’t have a firm idea of how foot size was related to overall body size in Australopithecus,” says evolutionary biologist Kevin Hatala of Chatham University in Pittsburgh. Masao’s group referred to size data from present-day humans to calculate heights and weights of A. afarensis footprint-makers. That approach “could lead to some error,” Hatala says. Stature estimates based on footprints face other obstacles, says paleoanthropologist Yohannes Haile-Selassie of the Cleveland Museum of Natural History. For instance, some tall individuals have small feet and short folks occasionally have long feet. It’s also unclear whether the new footprints and those from 1976 represent a single group, or if some smaller footprints were also made by males, Haile-Selassie adds. Cherin’s proposal that large A. afarensis males controlled female harems “is a bit of a stretch,” Haile-Selassie says. The new report doesn’t document surprisingly large size differences among members of Lucy’s kind, Haile-Selassie adds. A. afarensis fossils previously excavated in Ethiopia include a partial male skeleton now estimated by Haile-Selassie and his colleagues to have been only about three inches shorter than Chewie’s reported height (SN: 7/17/10, p. 5).
Haile-Selassie Y.,Cleveland Museum of Natural History
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2010
The earliest evidence of Australopithecus goes back to ca 4.2 Ma with the first recorded appearance of Australopithecus 'anamensis' at Kanapoi, Kenya. Australopithecus afarensis is well documented between 3.6 and 3.0 Ma mainly from deposits at Laetoli (Tanzania) and Hadar (Ethiopia). The phylogenetic relationship of these two 'species' is hypothesized as ancestor-descendant. However, the lack of fossil evidence from the time between 3.6 and 3.9 Ma has been one of its weakest points. Recent fieldwork in the Woranso-Mille study area in the Afar region of Ethiopia has yielded fossil hominids dated between 3.6 and 3.8 Ma. These new fossils play a significant role in testing the proposed relationship between Au. anamensis and Au. afarensis. The Woranso-Mille hominids (3.6-3.8 Ma) show a mosaic of primitive, predominantly Au. anamensis-like, and some derived (Au. afarensis-like) dentognathic features. Furthermore, they show that, as currently known, there are no discrete and functionally significant anatomical differences between Au. anamensis and Au. afarensis. Based on the currently available evidence, it appears that there is no compelling evidence to falsify the hypothesis of 'chronospecies pair' or ancestor-descendant relationship between Au. anamensis and Au. afarensis. Most importantly, however, the temporally and morphologically intermediate Woranso-Mille hominids indicate that the species names Au. afarensis and Au. anamensis do not refer to two real species, but rather to earlier and later representatives of a single phyletically evolving lineage. However, if retaining these two names is necessary for communication purposes, the Woranso-Mille hominids are best referred to as Au. anamensis based on new dentognathic evidence. © 2010 The Royal Society.
Hodgson C.J.,The National Museum of Wales |
Hardy N.B.,Cleveland Museum of Natural History
Systematic Entomology | Year: 2013
Currently, 49 families of scale insects are recognised, 33 of which are extant. Despite more than a decade of DNA sequence-based phylogenetic studies of scales insects, little is known with confidence about relationships among scale insects families. Multiple lines of evidence support the monophyly of a group of 18 scale insect families informally referred to as the neococcoids. Among neococcoid families, published DNA sequence-based estimates have supported Eriococcidae paraphyly with respect to Beesoniidae, Dactylopiidae, and Stictococcidae. No other neococcoid interfamily relationship has been strongly supported in a published study that includes exemplars of more than ten families. Likewise, no well-supported relationships among the 15 extant scale insect families that are not neococcoids (usually referred to as 'archaeococcoids') have been published. We use a Bayesian approach to estimate the scale insect phylogeny from 162 adult male morphological characters, scored from 269 extant and 29 fossil species representing 43/49 families. The result is the most taxonomically comprehensive, most resolved and best supported estimate of phylogenetic relationships among scale insect families to date. Notable results include strong support for (i) Ortheziidae sister to Matsucoccidae, (ii) a clade comprising all scale insects except for Margarodidae s.s., Ortheziidae and Matsucoccidae, (iii) Coelostomidiidae paraphyletic with respect to Monophlebidae, (iv) Eriococcidae paraphyletic with respect to Stictococcidae and Beesoniidae, and (v) Aclerdidae sister to Coccidae. We recover strong support for a clade comprising Phenacoleachiidae, Pityococcidae, Putoidae, Steingeliidae and the neococcoids, along with a sister relationship between this clade and Coelostomidiidae+Monophlebidae. In addition, we recover strong support for Pityococcidae+Steingeliidae as sister to the neococcoids. Data from fossils were incomplete, and the inclusion of extinct taxa in the data matrix reduced support and phylogenetic structure. Nonetheless, these fossil data will be invaluable in DNA sequence-based and total evidence estimates of phylogenetic divergence times. © 2013 The Royal Entomological Society.
Agency: NSF | Branch: Standard Grant | Program: | Phase: Biological Anthropology | Award Amount: 118.95K | Year: 2012
The early and middle Miocene (ca. 23 to 11 million years ago) witnessed an expansion of the worlds tropical and subtropical forests, and an increase in the diversity and distribution of mammals that thrived in forests with low seasonality and high productivity. Apes flourished under these conditions in the Old World. The contraction of subtropical forests in the late Miocene in Eurasia resulted in a decline in the diversity and abundance of apes, and the rise of monkeys and other mammals able to survive in more open and seasonal habitats. Several fossil sites in southern China provide evidence of this critical transition. In this project, the fossil site of Shuitangba, Yunnan Province, China, will be investigated because it has yielded the abundant and well-preserved remains of many mammal species of terminal Miocene age (~6.1 mya). Among them are an ape and a monkey, the first such co-occurrence in the Miocene of Eurasia. Recovery and detailed study of the fossils by an international team of American and Chinese investigators will make possible the characterization of the paleoenvironment of Shuitangba and the nature and adaptations of the sites many species, especially its primates and carnivores. Direct comparison of the Shuitangba biota with others of similar age in eastern Asia will provide a clearer idea of the nature and pace of environmental evolution in the region.
Shuitangba captures a unique snapshot of the transition from the widespread evergreen forests of the Miocene to the more heterogeneous and seasonal habitats that followed. This project thus promotes the understanding of an ecosystem poised at the tipping point of a major change. The Shuitangba fauna and environment provide an unusually clear picture of a distinctive regional ecosystem that contained long-established species alongside new arrivals. A better understanding of the adaptations of species within such ecosystems may shed light on the dynamics of modern unstable environments.
This project fosters strong international collaboration with Chinese scholars, including advanced training for Chinese paleoanthropologists, paleobiologists, and fossil preparators, and promotes public science education in China through media coverage and development of museum displays. A junior US scientist will be integrally involved in the research, and US undergraduate students also will receive substantial participatory research training.
Agency: NSF | Branch: Standard Grant | Program: | Phase: Digitization | Award Amount: 305.77K | Year: 2014
The rapid biodiversity change in North America has significant effects on essential ecosystem services, from impact on soil health and nutrient cycling, to agriculture, forestry and water quality. Exploding populations of invasive species threaten fresh water and terrestrial habitats and potentially impact the natural resources of the nation. Easy access to robust, expertly vetted baseline data for species occurrences, abundances, and distribution ranges, and monitoring how these parameters have changed through time, will facilitate the protection of the nations natural resources, and vastly improve the capacity for effective restoration, land management planning, and conservation management. Numerous undergraduate students will receive training in digitization technologies and a modular exhibit will be developed to engage public interest in biodiversity changes.
Effective monitoring requires easy electronic access to historical specimen baseline information for temporal and regional species diversity comparisons that can facilitate informed land management decisions. Vast amounts of specimen data are housed within the nations natural history collections, but most of these data are not readily accessible from digital resources. Size and complexity of scientific specimen collections require major technological advances in capturing specimen data. The goal of this four-year collaborative project is the rapid digitization of >2 million specimens and their locality data from ten arthropod and mollusk collections housed at six major US museums in six states (Il, OH, AL,MI, DE, PA). This project will significantly automate specimen data capture by utilizing optical character and voice-recognition technologies. The digitized data from this project will be immediately deployed for habitat-based distribution modeling and analyses.This award is made as part of the National Resource for Digitization of Biological Collections through the Advancing Digitization of Biological Collections program and all data resulting from this award will be available through the national resource (iDigBio.org).
Agency: NSF | Branch: Continuing grant | Program: | Phase: Systematics & Biodiversity Sci | Award Amount: 357.45K | Year: 2012
The charismatic predatory insect group of praying mantises (order Mantodea) includes over 2,400 described species that exhibit an incredibly rich diversity of morphology and life history strategies. Despite the long tradition of ecological, behavioral, and physiological research focused on the group, mantises have received limited taxonomic attention and the current classification scheme does not reflect genetically based, evolutionary relationships. This project will unify traditional and modern morphological and genetically based systematic methods to reconstruct the evolutionary relationships for all praying mantises, which will guide the construction of a natural classification that reflects true evolutionary groups. This research will also produce two species-level taxonomic monographs (representing about 21% of the praying mantis diversity) while building new museum collections, describing numerous new species, producing online, interactive identification keys for mantis genera, and producing a publicly accessible database of taxonomic information and scientific literature references.
This project will represent a significant first step in modernizing the systematics of these insects that are often used to control such pests as aphids. The project will also provide a model for future revisions of other insect groups. This research will impact the broader community by: 1) producing high-quality images of mantises and their morphology, organized in an evolutionary framework that will facilitate community identifications through online, interactive taxonomic keys; 2) opening annually scheduled workshops to include university students, high school teachers, and the public, which will provide information and training in praying mantis taxonomy, morphology, and biology; 3) providing new scientific training at the post-doctoral, graduate, and undergraduate student levels; and 4) immediately complementing current comparative research in mantis sexual ecology, prey recognition physiology, and auditory evolution by providing a stable and predictive classification.
Agency: NSF | Branch: Continuing grant | Program: | Phase: Biological Anthropology | Award Amount: 330.52K | Year: 2011
The research involves multidisciplinary field and laboratory work conducted in the Woranso-Mille study area of the Afar Depression in Ethiopia. The Woranso-Mille paleoanthropological project is relatively new and has started gathering significant fossil hominid specimens from a time period poorly known previously (3.6-3.8 million years ago). This funding supports collaborative research to be conducted by paleontologists, geologists, geochronologists, and paleoecologists from six institutions in the United States and abroad.
Scientists from each institution will coordinate their efforts to understand early hominid diversity between 3.0 and 4.0 million years ago, early Australopithecus paleobiology, taxonomy, and phylogenetic relationships, and establish their paleoenvironments. These will be attained by conducting detailed comparative analysis of the Woranso-Mille hominids enhanced by the use of High-resolution x-ray computed tomography, and isotope analysis in order to test whether morphological differences observed for the Woranso-Mille hominids correlate to isotopic variation that are indicative of behavioral and physiological differences. The paleontologists will further conduct faunal collection directed towards increasing the sample size of all fossil taxa at the site to increase biostratigraphic control, refine paleoenvironmental context of the associated hominids, and identify additional fossiliferous localities. Geologists of the project will establish a refined stratigraphic context for the fossils collected from all of the designated vertebrate localities in the northern part of the study area, establish refined stratigraphy and chronometric ages (using 40Ar/39Ar dating and magnetostratigraphy) for the vertebrate localities and associated fossils, and determine stratigraphic correlations across vertebrate localities within the study area and other paleontological sites in the region. The scientific results from this study will answer questions related to mid-Pliocene hominid diversity, generate new data on the paleobiology of early hominids and their paleohabitat, and increase understanding of mid-Pliocene African vertebrate evolution.
Broader impacts of this project focus on creating training opportunities for undergraduate and graduate students and postdoctoral fellows.
Agency: NSF | Branch: Continuing grant | Program: | Phase: ACTIVATION | Award Amount: 11.00K | Year: 2016
Animal behavior is affected by an individuals internal conditions. For example, as animals feed, their strategies for acquiring food changes. The impact of food odors has a very different effect on a hungry person than one who has just had a large meal. This project brings together laboratories from the Case Western Reserve University Biology department and the Cleveland Museum of Natural History to examine changes in hunting strategy that occur as praying mantises feed. The biology laboratory will examine changes in brain systems that control movement as the insect feeds or receives injections of hormones associated with feeding. Insects provide advantages for monitoring brain activity for long feeding periods. Results will demonstrate how brain systems that are altered by hormones associated with feeding affect hunting and will increase our general understanding of the mechanisms by which hormonal changes alter animal behavior. The museum laboratory will expand the study to a wider range of praying mantis species. The project also has a unique educational component. Project related material will be developed into new high- and middle-school teaching modules for the Cleveland Museum of Natural Historys award winning distance learning program, which has reached thousands of students in 48 states. These programs align with Ohios New Learning Standards. Modules will be offered for free for the duration of the project and 3 subsequent years.
The project focuses on the highly structured central complex insect brain region that has received much recent attention. Numerous forms of sensory information coupled with motor effects and the presence of behaviorally relevant neuromodulators imply an important role for the central complex in behavioral adaptation. Yet, no study has brought all these components together to demonstrate how these brain circuits generate context dependent adjustments in natural behavior. This project seeks do that by relating changes in praying mantis hunt strategies to central complex activity patterns recorded by multi-channel tetrode implants as the hunt takes place in one generalist and two specialist praying mantis species. Tetrode wires will be implanted in the insects central complex. Then after recovery the subject will be moved to an arena where it hunts either live prey (cockroach nymphs) or artificial prey (moving dots on a computer screen that makes up the floor of the arena). The artificial stimulus allows repeated trials to provide quantitative data on neural activity associated with hunting. Neural and behavioral changes will be documented as physiological state is modified by feeding or insulin injection. Comparative studies will clarify how evolution acts on brain structures to shape behavior for specific niches. Successful completion will be transformative both in our understanding of the central complexs role in behavioral adjustment and, more generally, in defining mechanisms by which brain regions in all animals can alter adaptive behavior, thereby establishing the praying mantis as a new general model for behavioral selection.
News Article | December 13, 2016
Female orchid mantises are dazzlingly beautiful, with pinkish legs that appear to form a delicate flower blossom. They're also double the size of their far plainer male counterparts. Typically, when insect females evolve to become much larger than males, it's to maximize the number of offspring they can produce. But scientists believe that female orchid mantises evolved into beautiful flower forms for a more sinister reason: to hunt prey. Researchers have traced the evolutionary history of the two known species of orchid mantises, found in Southeast Asia, using genetic analysis and evolutionary modeling. The evolutionary changes enhanced the female's predatory abilities, as the scientists recently described in Scientific Reports. Long ago, males and females were approximately the same size and had patterns that helped them to blend into the foliage as they waited to ambush prey, as Gavin Svenson, head of invertebrate zoology at the Cleveland Museum of Natural History, tells The Two-Way. "And then you have a small group within that overall lineage that has a significant increase in female size," he says, allowing them to hunt larger pollinators. At this point, Svenson says, "once you get a large female that [seek out and] overcome pollinators and feed on all these pollinators, then wouldn't it be better to just attract the pollinators yourself?" That's exactly what happened in the next evolutionary split, Svenson and his colleagues found. Instead of trying to blend into their surroundings with drab colors, the mantises evolved into the "crazy floral masqueraders" they are now. Instead of lying in wait for a pollinator to come to a flower, they became the "flowers" themselves. And they're really good at being "flowers" — in fact, Svenson says that pollinators are more attracted to orchid mantises than they are to actual flowers. In short, once these female mantises "weren't restricted by male morphology anymore," they really started to blossom. Wondering what the female orchid mantis looks like in action? Take a look at them hunting in this National Geographic video: The males remained small and plain primarily in order to seek mates, Svenson says. From an evolutionary perspective, if the male "had to deal with the same type of lifestyle, it would be really difficult for him to go out and find females and mate with females." Svenson explains: The team's conclusion that female predation, not fecundity, drove the orchid mantis' evolution is surprising. In fact, the paper states that it is the first time that pattern has been found in an arthropod lineage. But Svenson says it speaks to a larger point about insect evolution. "Insects are so diverse," he says, "and they're doing so many different things that to say there's a general trend of anything in insect diversity is probably a bad idea ... because there's something somewhere that will violate that."