REVIEW | doi:10.20944/preprints202003.0438.v1
Subject: Biology, Animal Sciences & Zoology Keywords: history of science; study of invertebrates; research patterns; study of velvet worms
Online: 30 March 2020 (04:46:22 CEST)
Velvet worms, or onychophorans, include placental species and, as a phylum, have survived all mass extinctions since the Cambrian. They capture prey with an extraordinary adhesive net that appears in an instant. The first naturalist to formally mention them was Lansdown Guilding (1797-1831), a British priest from the Caribbean island of Saint Vincent. His life is as little known as the history of the field he initiated, onychophorology. This is the first general history of onychophorology, and I have divided it into half century periods. The beginning, 1826-1879, was defined by former students of great names in the history of biology, like Cuvier and von Baer. This generation included Milne-Edwars and Blanchard, and the greatest advances came from France, with smaller but still important contributions from England and Germany. In the 1880-1929 period, work concentrated in anatomy, behavior, biogeography and ecology, but of course the most important work was Bouvier’s mammoth monograph. The next half century, 1930-1979, was important for the discovery of Cambrian species; Vachon’s explanation of how ancient distribution defined the existence of two families; Pioneer DNA and electron microscopy from Brazil; and primitive attempts at systematics using embryology or isolated anatomical characteristics. Finally, the 1980-2020 period, with research centered in Australia, Brazil, Costa Rica and Germany, is marked by an evolutionary approach to everything, from body and behavior to distribution; for the solution of the old problem of how they form their adhesive net and how the glue works; the reconstruction of Cambrian onychophoran communities, the first experimental taphonomy; the first country-wide map of conservation status (from Costa Rica); the first model of why they survive in cities; the discovery of new phenomena like food hiding, parental feeding investment and ontogenetic diet shift; and for the birth of a new research branch, Onychophoran Ethnobiology, founded in 2015. While a few names appear often in the literature, most knowledge was produced by a mass of researchers who entered the field only briefly.
ARTICLE | doi:10.20944/preprints201812.0158.v1
Subject: Arts & Humanities, Anthropology & Ethnography Keywords: monster of troy; archaeology; Corinthian vase; fossil; Samotherium
Online: 13 December 2018 (06:47:37 CET)
It has been proposed that the Monster of Troy, depicted in a 6th Century BC Corinthian vase, is the earliest artistic record of a vertebrate fossil, possibly a Miocene giraffe (Samotherium sp.). I analyzed the giraffe hypothesis under four approaches: a double-blind random design in which 78 biologists compared the vase skull with Samotherium and several reptiles; an informed survey of 30 students who critically assessed the hypothesis; a computerized image comparison; and a morphological comparison. All of them rejected the giraffe hypothesis. Eye and teeth types unambiguously discard a fossil or living mammal as the model, which more probably was an extant carnivorous reptile.
ARTICLE | doi:10.20944/preprints201810.0669.v1
Subject: Biology, Ecology Keywords: scorpion ecology; multivariate statistics; body size; offspring characteristics, K and r strategists
Online: 29 October 2018 (10:09:45 CET)
There are no studies that quantitatively compare life histories among scorpion species. Statistical procedures applied to 94 scorpion species indicate that those with larger bodies do not necessarily have larger litters or longer life cycles, opposite to some theoretical predictions.
ARTICLE | doi:10.20944/preprints201812.0151.v1
Subject: Biology, Ecology Keywords: Peripatidae, conservation status, survival, urban populations, threatened species
Online: 12 December 2018 (14:07:09 CET)
ABSTRACT: Charismatic species, like the panda, play an important role in conservation, and velvet worms arguably are charismatic worms. Thanks to their extraordinary hunting mechanism, they have inspired from a female metal band in Japan, to origami worms in Russia and video game monsters in the USA. Objective: To assess their conservation status in Costa Rica. Methods: we located all collection records of the 29 known species from the Onychophora Database in the map of the Costa Rican Conservation Network. Results: We found that seven species are protected inside forest reserves, five in Protected Zones, four in Wildlife Refuges, two in National Parks and one, Principapillatus hitoyensis, in a strictly pristine Biological Reserve. The largest species in the world, Peripatus solorzanoi, occurs both inside a Forest Reserve and in protected private land. Protection inside Costa Rican nature areas is enforced year round by personnel that includes armed guards, and is supported by educational programs in surrounding communities. Twelve species have not been found in protected areas, but in Costa Rica, all biological species, named and unnamed, are protected by law and cannot be legally collected, or exported, without technically issued permits. Conclusion: Like in the only other country with similar information (New Zealand), the conservation of onychophorans seems to be of least concern for at least two thirds of the known species. Epiperipatus isthmicola, recently rediscovered after a century of absence in collections, can be considered Threatened because nearly all of its natural habitat has now been covered by a city.
ARTICLE | doi:10.20944/preprints201908.0123.v1
Subject: Biology, Ecology Keywords: snake demography; moonlight; rain; temperature; climate change in Osa
Online: 11 August 2019 (05:35:15 CEST)
Introduction: studies in the last two decades have found declining snake populations in both temperate and tropical sites, including informal reports from Drake Bay, Costa Rica. Objective: to investigate if reports of decreasing snake populations in Drake Bay had a real basis, and if environmental factors, particularly temperature, rain and light, have played a role in that decrease. Methods: we worked at Drake Bay from 2012 through 2017 and made over 4000 h of transect counts. Using head flashlights we surveyed a transect covered by lowland tropical rainforest at an altitude of 12–38 m above sea level, near the Agujas River, mostly at 1930–2200 hours. We counted all the snakes that we could see along the transect. Results: snake counts increase from August to September and then decline rapidly. The May snakes/rainfall peaks coincide, but the second snake peak occurs one month before the rain peak; we counted more snakes in dry nights, with the exception of Imantodes cenchoa which was equally common despite rain conditions. We saw less Leptodeira septentrionalis on bright nights, but all other species were unaffected. Along the six years, the number of species with each diet type remained relatively constant, but the number of individuals declined sharply for those that feed on amphibians and reptiles. We report Rhadinella godmani, a highland species, at 12–38 m of altitude. Conclusion: night field counts of snakes in Drake Bay, Costa Rica, show a strong decline from 2012 through 2017.