Giants Among Micromorphs: Were Cincinnatian (Ordovician, Katian) Small Shelly Phosphatic Faunas Dwarfed?, Benjamin F. Dattilo, Rebecca L. Freeman, Winfried S. Peters, William P. Heimbrock, Bradley Deline, Anthony J. Martin, Jack W. Kallmeyer, Jesse Reeder, Anne Argast
Feb 2016
Giants Among Micromorphs: Were Cincinnatian (Ordovician, Katian) Small Shelly Phosphatic Faunas Dwarfed?, Benjamin F. Dattilo, Rebecca L. Freeman, Winfried S. Peters, William P. Heimbrock, Bradley Deline, Anthony J. Martin, Jack W. Kallmeyer, Jesse Reeder, Anne Argast
Winfried S. Peters
Small fossils are preserved as phosphatic (carbonate fluorapatite) micro-steinkerns (∼ 0.5 mm diameter) in Upper Ordovician beds of the Cincinnati area. Mollusks are common, along with bryozoan zooecia, echinoderm ossicles, and other taxa. Similar occurrences of Ordovician micromorphic mollusks have been interpreted as ecologically dwarfed and adapted to oxygen-starved conditions, an interpretation with implications for ocean anoxia. An alternative explanation for small phosphatic steinkerns is taphonomic. Stable carbonate fluorapatite selectively filled small voids, thus preserving small fossils, including larval/young mollusks. Reworking concentrated small phosphatic steinkerns from multiple generations while larger, unfilled calcareous shells were destroyed, resulting in small fossils progressively …
Cannibalism Causes Size-Dependent Intraspecific Predation Pressure But Does Not Trigger Autotomy In The Intertidal Gastropod Agaronia Propatula, Ariel Z. Cyrus, Jennifer Swiggs, Pilar Santidrian Tomillo, Frank V. Paladino, Winfried S. Peters
Aug 2015
Cannibalism Causes Size-Dependent Intraspecific Predation Pressure But Does Not Trigger Autotomy In The Intertidal Gastropod Agaronia Propatula, Ariel Z. Cyrus, Jennifer Swiggs, Pilar Santidrian Tomillo, Frank V. Paladino, Winfried S. Peters
Winfried S. Peters
Autotomy of the foot is readily inducible in the predatory marine gastropod Agaronia propatula (Conrad, 1849), but the natural trigger of the autotomy response is obscure. Since cannibalistic predation has been observed in the species while interspecific predation on A. propatula has not, it was hypothesized that autotomy in A. propatula helps to defend against cannibalism. This hypothesis was tested in the present study. In our Costa Rican study population, autotomy as well as cannibalism occurred at significant rates; morphological indicators of foot regeneration suggested that 9–23% of the animals had autotomized previously, while about 5% of all observed predation …
The Cannibalistic Snail Agaronia Propatula Is Reluctant To Feed On Autotomized ‘Tails’ Of Conspecifics, Ariel Z. Cyrus, Winfried S. Peters
Jun 2014
The Cannibalistic Snail Agaronia Propatula Is Reluctant To Feed On Autotomized ‘Tails’ Of Conspecifics, Ariel Z. Cyrus, Winfried S. Peters
Winfried S. Peters
Autotomy and cannibalism increase the complexity of the life history, population structure, and population dynamics of a species. Species in which autotomy is triggered by cannibalism have rarely been studied. It has been hypothesized that in the intertidal gastropod Agaronia propatula, autotomized tissues are highly attractive to cannibals and so increase the victim’s chance to escape. We tested the hypothesis by presenting autotomized ‘tails’ to foraging animals. The attack rates on autotomized ‘tails’ were lower than those on artificial objects reported previously. Autonomously moving autotomized ‘tails’ were more frequently ignored than non-moving and artificially moved ‘tail’ pieces. Thus, autotomized …
What Can We Learn From Confusing Olivella Columellaris And O. Semistriata, Two Key Species In Panamic Sandy Beach Ecosystems?, Alison Troost, Samantha Rupert, Ariel Cyrus, Frank Paladino, Benjamin Dattilo, Winfried Peters
Jun 2012
What Can We Learn From Confusing Olivella Columellaris And O. Semistriata, Two Key Species In Panamic Sandy Beach Ecosystems?, Alison Troost, Samantha Rupert, Ariel Cyrus, Frank Paladino, Benjamin Dattilo, Winfried Peters
Winfried S. Peters
Olivella columellaris (Sowerby 1825) and O. semistriata (Gray 1839) are suspension feeding, swash surfing snails on tropical sandy beaches of the east Pacific. While they often are the numerically dominant macrofaunal element in their habitats, their biology is poorly understood; the two species actually have been confused in all of the few publications that address their ecology. Frequent misidentifications in publications and collections contributed also to an overestimation of the geographic overlap of the two species. To provide a sound taxonomic basis for further functional, ecological, and evolutionary investigations, we evaluated the validity of diagnostic traits in wild populations and …
The Behavioural And Sensory Ecology Of Agaronia Propatula (Caenogastropoda, Olividae), A Swash-Surfing Predator On Sandy Beaches Of The Panamic Faunal Province, Ariel Cyrus, Samantha Rupert, Amy Silva, Monika Graf, Jeremy Rappaport, Frank Paladino, Winfried Peters
Mar 2012
The Behavioural And Sensory Ecology Of Agaronia Propatula (Caenogastropoda, Olividae), A Swash-Surfing Predator On Sandy Beaches Of The Panamic Faunal Province, Ariel Cyrus, Samantha Rupert, Amy Silva, Monika Graf, Jeremy Rappaport, Frank Paladino, Winfried Peters
Winfried S. Peters
The genus Agaronia includes dominant predators in the eulittoral zone of dissipative sandy beaches of the tropical Eastern Pacific, which show specific adaptations to this environment such as swash-surfing locomotion. We studied A. propatula in its natural habitat in El Salvador and Costa Rica, and performed field experiments to obtain insights into its ecology, behaviour and sensory physiology. Agaronia propatula is not attracted by carrion and preys mostly on the ubiquitous beach snail Olivella semistriata. This, however, reflects community composition rather than prey specialization; A. propatula is an investigative hunter and will, quite literally, attack everything that moves (with …
Autotomy Of The Posterior Foot In Agaronia Propatula (Caenogastropoda: Olividae) Occurs In Animals That Are Fully Withdrawn Into Their Shells, Samantha D. Rupert, Winfried S. Peters
Oct 2011
Autotomy Of The Posterior Foot In Agaronia Propatula (Caenogastropoda: Olividae) Occurs In Animals That Are Fully Withdrawn Into Their Shells, Samantha D. Rupert, Winfried S. Peters
Winfried S. Peters
This paper has no abstract; this is the first paragraph. Autotomy is the active shedding of a body part which occurs in a variety of emergency situations including attacks by predators (Stasek, 1967; McVean, 1975; Maginnis, 2006). The immediate advantage of autotomy – surviving an otherwise deadly attack – comes at a price, which may include physical, energetic, behavioural and reproductive costs (Cooper, 2003; Maginnis, 2006). While the evolutionary and ecological consequences of autotomy have been studied most thoroughly in lizards (Clause & Capaldi, 2006; Bateman & Fleming, 2009), the phenomenon also is known from numerous invertebrate taxa, where it …
Legume Phylogeny And The Evolution Of A Unique Contractile Apparatus That Regulates Phloem Transport, Winfried Peters, Claudia Hanakam, Dietmar Haffer, Aart Van Bel, Michael Knoblauch
Mar 2010
Legume Phylogeny And The Evolution Of A Unique Contractile Apparatus That Regulates Phloem Transport, Winfried Peters, Claudia Hanakam, Dietmar Haffer, Aart Van Bel, Michael Knoblauch
Winfried S. Peters
Protein bodies called forisomes undergo Ca2+-dependent deformations to occlude sieve tubes reversibly, providing a unique regulatory mechanism of phloem transport. Because forisomes are known exclusively from the Papilionoideae (Leguminosae), the evolution of forisome function may have played a role in the rapid radiation of this huge taxon. The unexpected discovery of a papilionoid species lacking forisomes led us to evaluate a representative set of species covering 33 of the 36 legume tribes traditionally recognized. We found forisomes in Papilionoideae but not in Caesalpinioideae and Mimosoideae. Forisomes were absent from several species of the papilionoid tribe Galegeae. Forisomes with tail-like protrusions …
Sexual Size Dimorphism (Ssd) Is The Most Consistent Explanation For The Body Size Spectrum Of Confuciusornis Sanctus, Winfried S. Peters, Dieter Stefan Peters
Mar 2010
Sexual Size Dimorphism (Ssd) Is The Most Consistent Explanation For The Body Size Spectrum Of Confuciusornis Sanctus, Winfried S. Peters, Dieter Stefan Peters
Winfried S. Peters
This paper has no abstract; this is the first paragraph. Recently, we suggested that the size spectrum of Confuciusornis sanctus is best explained by sexual size dimorphism (SSD) and is compatible with a bird-like life history (Peters & Peters 2009). We find the criticism of Chiappe et al. (2010) interesting, but irrelevant to our main argument.
Life History, Sexual Dimorphism And 'Ornamental' Feathers In The Mesozoic Bird Confuciusornis Sanctus., Winfried S. Peters, Dieter Stefan Peters
Sep 2009
Life History, Sexual Dimorphism And 'Ornamental' Feathers In The Mesozoic Bird Confuciusornis Sanctus., Winfried S. Peters, Dieter Stefan Peters
Winfried S. Peters
The life history of Confuciusornis sanctus is controversial. Recently, the species’ body size spectrum was claimed to contradict osteohistological evidence for a rapid, bird-like development. Moreover, sexual size dimorphism was rejected as an explanation for the observed bimodal size distribution since the presence of elongated rectrices, an assumed ‘male’ trait, was uncorrelated with size. However, this interpretation (i) fails to explain the size spectrum of C. sanctus which is trimodal rather than bimodal, (ii) requires implausible neonate masses and (iii) is not supported by analogy with sexual dimorphisms in modern birds, in which elongated central rectrices are mostly sex-independent. Available …
An Outline Of A Theory Of The Constructional Constraints Governing Early Organismic Evolution, Winfried S. Peters, Bernd Herkner
Jun 2000
An Outline Of A Theory Of The Constructional Constraints Governing Early Organismic Evolution, Winfried S. Peters, Bernd Herkner
Winfried S. Peters
This paper has no abstract; this is the first paragraph. The origin of life is one of the most fascinating biological enigmas (Dyson 1985, de Duve 1991). A multitude of hypotheses is available, ranging from the classical "primordial broth" (Haldane 1929) to the "genetic takeover" (Cairns-Smith 1982). Most of these models center on biochemical, metabolic, or genetic aspects. To our knowledge a comprehensive investigation into the mechanical constraints governing the early development of organismic constructions is not available to date. Attempting to close this gap, we here present an outline of a theory of the transformation of constructions in early …
Anpassung - Kernpunkt Oder Mißverständnis Der Evolutionstheorie? [Adaptation - Essential Concept Or Misconception Of Evolutionary Biology?], Dieter Stefan Peters, Winfried Peters
Dec 1996
Anpassung - Kernpunkt Oder Mißverständnis Der Evolutionstheorie? [Adaptation - Essential Concept Or Misconception Of Evolutionary Biology?], Dieter Stefan Peters, Winfried Peters
Winfried S. Peters
Die Grundzüge des Gesagten lassen sich folgendermaßen zusammenfassen:
- Die Organismen sind in der Evolution keine Objekte, sondern weitgehend autonome Subjekte. Die evolutive Transformation ihrer Konstruktion erfolgt nach Maßgabe ihrer jeweils bereits vorhandenen Strukturen.
- In Abhängigkeit von ihren jeweiligen konstruktiven Möglichkeiten wandern Organismen in Lebensräume ein und schaffen sich ihre Nischen. Was und wie eine ökologische Nische ist, bestimmt sich dabei vom Organismus her. Die Annahme, daß im Selektionsprozeß die Umwelt die Organismen sich anverwandelt, ist theoretisch unnötig, faktisch zweifelhaft, und darüberhinaus entgegen verbreiteter Ansicht von äußerst beschränktem Wert für die phylogenetische Forschungspraxis.
- Die Umwelt taugt nicht zur …
Pollination Of The Crown Imperial Fritillaria Imperialis By Great Tits Parus Major, Winfried S. Peters, Michael Pirl, Gerhard Gottsberger, Dieter Stefan Peters
Feb 1995
Pollination Of The Crown Imperial Fritillaria Imperialis By Great Tits Parus Major, Winfried S. Peters, Michael Pirl, Gerhard Gottsberger, Dieter Stefan Peters
Winfried S. Peters
Visitations of flowers of the Crown Imperial by Great Tits at two different locations in Hessen, Germany, in 1990 and 1993 are described. The observations prove that flowers were visited because of the nectar; most likely pollination occurs during this visits. Similar reports from Europe are discussed. The significance of specific interactions including ecological generalists such as the Great Tit is considered in the context of the phylogenetic reconstruction of the development of co-adaptive syndroms.
Die Konsequenzen Eines Lebens Im Druckbehälter. Biotheoretische Implikationen Der Organisation Pflanzlicher Organismen [The Consequences Of Living In A Pressure Pot. Biotheoretical Implications Of The Organismic Architecture Of Plants], Winfried Peters, Hubert Felle
Jun 1992
Die Konsequenzen Eines Lebens Im Druckbehälter. Biotheoretische Implikationen Der Organisation Pflanzlicher Organismen [The Consequences Of Living In A Pressure Pot. Biotheoretical Implications Of The Organismic Architecture Of Plants], Winfried Peters, Hubert Felle
Winfried S. Peters
Die Betrachtung der sich aus der zellulären Osmo- und Druckregulation ergebenden konstruktiven Zwänge erlaubt es, invariante Eigenschaften makroskopischer Pflanzen abzuleiten. Sessilität wird als grundsätzlich unumgänglich erkannt; Autotrophie als zwangsläufige Ernährungsform kann nur durch Parasitismus oder Beteiligung an Symbiosen umgangen werden. Hieraus ergibt sich die Antwort auf die Frage nach dem “Unterschied” zwischen Tieren und Pflanzen: die Bildung clonarer Kolonien (Metapopulationen) kann bei sessilen Organismen besonders plausibel begründet werden, zumal, wenn diese autotroph leben. Sessilität stellt bei Tieren eine Option, bei makroskopischen Pflanzen aber eine Notwendigkeit dar. Das Vorherrschen des Konstruktionstyps “Metapopulation” bei Pflanzen ist damit vorgezeichnet; dies ist letztlich eine …
