scholarly journals The evolution of the flippers and the paleoecology of Panchelonioidea (Testudines, Cryptodira)

Author(s):  
Isadora Gerheim ◽  
Pedro S. R. Romano

Background. The recent data on Panchelonioidea’s phylogeny suggested the family level relationships as (Toxochelyidae, (Cheloniidae, (Protostegidae, Dermochelyidae))). Despite the similarity between their limbs, it is known that the flippers morphology on marine turtles evolved independently in these clades. A remarkable feature is the presence of phalangeal condyles in Toxochelyidae and basal Protostegidae, a plesiomorphic state that allows the movement of the hand. On the other hand, the apomorphic state of having a rigid paddle is found in modern turtles (Cheloniidae and Dermochelyidae). Also, living Chelonioidea (Cheloniidae and Dermochelyidae) has the longest length of the hand and the shortest length of the humerus compared to other Testudines, as analyzed by Joyce and Gauthier (2004, Proc. R. Soc. Lond. B, 271). Methods. We took measurements of the forelimb (the length of humerus, ulna and digit III) from five Panchelonioidea fossil species (Protostega gigas, Toxochelys latiremys, Allopleuron hoffmanni, Eochelone brabantica and Archelon ischyros) using ImageJ 1.48v. The percentages of the length of the hand and the humerus with respect to the whole limb were then calculated. The percentages of the five species were added to the two-dimension ternary diagram made by Joyce and Gauthier (2004) in order to evaluate the plot of these species and compare them to other turtles. Results. Archelon ischyros was plotted near Toxochelys latiremys. The Toxochelidae are the sister group of Chelonioidea and they are known to have a poor development of the limbs into flippers and a preference for shallow and benthic habitat. Both were located near non-marine turtle species, showing that they had the relatively shortest hand within Panchelonioidea, whereas Protostega gigas, Allopleuron hoffmanni and Eochelone brabantica was plotted close to the recent Cheloniidae. Discussion. The results suggest a less pelagic habitat for Protostega gigas and Archelon ischyros, resembling a hypothesis formulated by Hay (1905, Bull. Am. Mus. Nat. Hist., 21) that Archelon was not as pelagic as Dermochelys and by Wieland (1909, Am. Jour. Sci., 27) that this species did not have a powerful type of muscular insertion, maybe indicating a less strong swimming power. These results together with the fact that basal species of Protostegidae retain the phalangeal condyles, suggests that after the split between these families, the flippers retained the primitive length of limbs. It also brings back a Zangerl’s hypothesis (1980, Amer. Zool., 20) of a Chelydra-like ancestor for Panchelonioidea, with unspecialized limbs. As conclusion, we suggest that Panchelonioidea ancestor flipper condition would last in stem Toxochelyidae and stem Chelonioidea and then get independently specialized in Cheloniidae and Dermochelyidae.

2015 ◽  
Author(s):  
Isadora Gerheim ◽  
Pedro S. R. Romano

Background. The recent data on Panchelonioidea’s phylogeny suggested the family level relationships as (Toxochelyidae, (Cheloniidae, (Protostegidae, Dermochelyidae))). Despite the similarity between their limbs, it is known that the flippers morphology on marine turtles evolved independently in these clades. A remarkable feature is the presence of phalangeal condyles in Toxochelyidae and basal Protostegidae, a plesiomorphic state that allows the movement of the hand. On the other hand, the apomorphic state of having a rigid paddle is found in modern turtles (Cheloniidae and Dermochelyidae). Also, living Chelonioidea (Cheloniidae and Dermochelyidae) has the longest length of the hand and the shortest length of the humerus compared to other Testudines, as analyzed by Joyce and Gauthier (2004, Proc. R. Soc. Lond. B, 271). Methods. We took measurements of the forelimb (the length of humerus, ulna and digit III) from five Panchelonioidea fossil species (Protostega gigas, Toxochelys latiremys, Allopleuron hoffmanni, Eochelone brabantica and Archelon ischyros) using ImageJ 1.48v. The percentages of the length of the hand and the humerus with respect to the whole limb were then calculated. The percentages of the five species were added to the two-dimension ternary diagram made by Joyce and Gauthier (2004) in order to evaluate the plot of these species and compare them to other turtles. Results. Archelon ischyros was plotted near Toxochelys latiremys. The Toxochelidae are the sister group of Chelonioidea and they are known to have a poor development of the limbs into flippers and a preference for shallow and benthic habitat. Both were located near non-marine turtle species, showing that they had the relatively shortest hand within Panchelonioidea, whereas Protostega gigas, Allopleuron hoffmanni and Eochelone brabantica was plotted close to the recent Cheloniidae. Discussion. The results suggest a less pelagic habitat for Protostega gigas and Archelon ischyros, resembling a hypothesis formulated by Hay (1905, Bull. Am. Mus. Nat. Hist., 21) that Archelon was not as pelagic as Dermochelys and by Wieland (1909, Am. Jour. Sci., 27) that this species did not have a powerful type of muscular insertion, maybe indicating a less strong swimming power. These results together with the fact that basal species of Protostegidae retain the phalangeal condyles, suggests that after the split between these families, the flippers retained the primitive length of limbs. It also brings back a Zangerl’s hypothesis (1980, Amer. Zool., 20) of a Chelydra-like ancestor for Panchelonioidea, with unspecialized limbs. As conclusion, we suggest that Panchelonioidea ancestor flipper condition would last in stem Toxochelyidae and stem Chelonioidea and then get independently specialized in Cheloniidae and Dermochelyidae.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam G. Clause ◽  
Aaron J. Celestian ◽  
Gregory B. Pauly

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.


2017 ◽  
Vol 4 (8) ◽  
pp. 170153 ◽  
Author(s):  
Alexander R. Gaos ◽  
Rebecca L. Lewison ◽  
Michael P. Jensen ◽  
Michael J. Liles ◽  
Ana Henriquez ◽  
...  

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles ( Eretmochelys imbricata ) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.


1992 ◽  
Vol 6 ◽  
pp. 107-107
Author(s):  
Timothy J. Gaudin ◽  
William D. Turnbull

The mammalian order Xenarthra (including the living Neotropical armadillos, anteaters, and tree sloths) has figured importantly in recent hypotheses of interordinal relationships among eutherian mammals. It has been suggested that the group shares a common ancestry both with the extant Old World order Pholidota (i.e. the pangolins or scaly-anteaters) and the extinct North American group Palaeanodonta. Furthermore, these three groups have been linked together into a monophyletic Cohort Edentata, which has been hypothesized to represent the sister-group to all other eutherians. This placement of edentates relative to the remainder of Eutheria has been supported in part by a purported difference in the morphology of the stapes in the two groups- edentates possessing a primitive, imperforate/columelliform morphology, other placentals a derived, perforate/stirrup-shaped morphology.A recent study of stapedial morphology among mammals by Novacek and Wyss (1986) suggests that within the Xenarthra itself a perforate stapes is found among armadillos, but that the pilosa in particular (the clade including anteaters and sloths) and the order as a whole are characterized primitively by an imperforate stapes. Our studies of the xenarthran ear region (Patterson et al., in press) have uncovered new ontogenetic and paleontological evidence which contradict the findings of Novacek and Wyss. Among adults of the two extant tree sloth genera, the stapes lacks a stapedial foramen. However, in both genera, this adult imperforate morphology is derived from a perforated juvenile stapes. Novacek and Wyss ignored fossil species in their consideration of the xenarthran stapes. It has long been known that extinct ground sloths of the family Mylodontidae possessed a large stapedial foramen. Unfortunately, until now no stapes were known from the remaining ground sloth families, the Megatheriidae and the Megalonychidae. We have uncovered a complete left stapes of an early Miocene megatheriid ground sloth Eucholoeops ingens. This stapes possesses a well-developed stapedial foramen. We believe that this new paleontological evidence, combined with our information on the ontogeny of the stapes in the living genera, clearly indicates that a perforate stapes is primitive for sloths. Moreover, when we plot distributions of stapedial morphologies of both living and fossil edentates onto a phylogeny of the Edentata, we can demonstrate that the a large stapedial foramen is primitive for the Xenarthra as a whole, and probably for the entire Cohort Edentata. Such a distribution makes it unlikely that stapedial morphology can be used to separate edentates from other eutherian mammals.


2011 ◽  
Vol 279 (1731) ◽  
pp. 1093-1099 ◽  
Author(s):  
Maria Heikkilä ◽  
Lauri Kaila ◽  
Marko Mutanen ◽  
Carlos Peña ◽  
Niklas Wahlberg

Although the taxonomy of the ca 18 000 species of butterflies and skippers is well known, the family-level relationships are still debated. Here, we present, to our knowledge, the most comprehensive phylogenetic analysis of the superfamilies Papilionoidea, Hesperioidea and Hedyloidea to date based on morphological and molecular data. We reconstructed their phylogenetic relationships using parsimony and Bayesian approaches. We estimated times and rates of diversification along lineages in order to reconstruct their evolutionary history. Our results suggest that the butterflies, as traditionally understood, are paraphyletic, with Papilionidae being the sister-group to Hesperioidea, Hedyloidea and all other butterflies. Hence, the families in the current three superfamilies should be placed in a single superfamily Papilionoidea. In addition, we find that Hedylidae is sister to Hesperiidae, and this novel relationship is supported by two morphological characters. The families diverged in the Early Cretaceous but diversified after the Cretaceous–Palaeogene event. The diversification of butterflies is characterized by a slow speciation rate in the lineage leading to Baronia brevicornis , a period of stasis by the skippers after divergence and a burst of diversification in the lineages leading to Nymphalidae, Riodinidae and Lycaenidae.


Fossil Record ◽  
2020 ◽  
Vol 23 (2) ◽  
pp. 215-236
Author(s):  
Volker Lohrmann ◽  
Qi Zhang ◽  
Peter Michalik ◽  
Jeremy Blaschke ◽  
Patrick Müller ◽  
...  

Abstract. Rhopalosomatidae, currently considered the sister group of the Vespidae, are an enigmatic family of aculeate wasps that originated in the Late Jurassic or Early Cretaceous. Despite their considerable age, very few fossils of the family have been reported – all of them in amber (Miocene Dominican, Miocene Mexican, and mid-Cretaceous Burmese ambers). Here we report a new mid-Cretaceous rhopalosomatid wasp, Cretolixon alatum Lohrmann, gen. et sp. nov., from Burmese (Kachin) amber. This new genus has a unique mixture of characters, some of which are only known from the recent brachypterous genus Olixon and others of which are known only from the recent macropterous genera. Thus, Cretolixon Lohrmann, gen. nov. not only provides further evidence for the monophyly of the family but also contributes evidence for the monophyly of the Rhopalosomatinae. Key characters of the family are discussed, and an updated checklist of the world genera and fossil species and occurrences of Rhopalosomatidae is provided. Additionally, a chemical analysis was performed for three of the newly reported fossils as well as for the amber piece containing the rhopalosomatid larva described by Lohrmann and Engel (2017) to ascertain their amber vs. copal nature and their affinities with each other and previously described Burmese amber.


1988 ◽  
Vol 66 (12) ◽  
pp. 2797-2810 ◽  
Author(s):  
François Chapleau ◽  
Allen Keast

This article presents the phylogenetic conclusions of an osteological study of species belonging to the subfamilies (Soleinae and Achirinae) of the dextral flatfish family Soleidae (Pieuronectiformes; Soleoidei). A cladistic analysis of the data revealed that the subfamilies, but not the family, are monophyletic. The Soleinae were found to be more closely related to the other soleoid family, the Cynoglossidae, than to the Achirinae. If we accept the principle that only monophyletic groups are to be admitted into Linnean classification, it is suggested that the two subfamilies be raised to the family level. The anatomical data led to the proposal (with caution) that the sister group of the achirid–soleid–cynoglossid lineage is the pleuronectid subfamily Samarinae. Consequently, it is suggested that the suborder Soleoidei be eliminated by incorporating its three families into the Pleuronectoidei which becomes monophyletic. Also, it is proposed that the Pleuronectid subfamilies (Pleuronectinae, Poecilopsettinae, Paralichthodinae, Rhombosoleinae, Samarinae) be raised to the family level. However, since the monophyletic status of these taxa is dubious (except for the Samarinae) any hypothesis including them must await a proper cladistic analysis of their intra- and inter-relationships.


2020 ◽  
Vol 29 (4) ◽  
pp. 1135-1152 ◽  
Author(s):  
Liliana P. Colman ◽  
Paulo H. Lara ◽  
Jonathan Bennie ◽  
Annette C. Broderick ◽  
Juliana R. de Freitas ◽  
...  

AbstractCoastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species—leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles—are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992–1996 and 2008–2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles.


1994 ◽  
Vol 25 (1) ◽  
pp. 63-88 ◽  
Author(s):  
Joel Minet

AbstractThis paper is chiefly aimed at reassessing the limits of four bombycoid families, namely the Eupterotidae, Saturniidae, Lemoniidae, and Brahmaeidae. An incompletely resolved cladogram is proposed for the whole 'bombycoid complex' (Mimallonoidea + Lasiocampoidea + Bombycoidea). Within the Bombycoidea, the primary dichotomy is considered to lie between the Eupterotidae + Bombycidae s.lat. + Endromidae + Mirinidae + Saturniidae, and the Carthaeidae + Lemoniidae + Brahmaeidae + Sphingidae. Sharing at least nine synapomorphies, the Lemoniidae and Brahmaeidae are regarded as reliable sister groups, and the Lemoniidae + Brahmaeidae are proposed as a sister group to the Sphingidae. Another newly proposed clade groups together the Endromidae, Mirinidae and Saturniidae. At family level, the Hibrildidae are synonymized with the Eupterotidae (syn. n.), for which the most significant autapomorphy lies in a previously unnoticed particularity of the female hind leg (distitarsus typically provided with a midventral row of spines). Sexual dimorphism in leg structure also leads to a redefinition of the Saturniidae, a family which must include, with subfamily rank (stat. rev.), the 'Oxytenidae' and 'Cercophanidae' of modern authors. A pair of distal, tooth-like structures on the fourth tarsomere of the female fore leg can thus be ascribed to the ground plan of the Saturniidae, along with a few other convincing autapomorphies. On the other hand, the 'Apatelodidae' are only tentatively placed in the 'Bombycidae sensu lato', a group provisionally resurrected insofar as the Apatelodidae sensu auct. prove to be diphyletic. As a matter of fact, the 'apatelodid' subfamily Epiinae is synonymized with the Bombycinae (syn. n.) in consideration of a rather large number of synapomorphies. When more extensively studied, the morphology of the eighth sternum of the male abdomen might lead to a slightly different, more restricted, concept of the Bombycidae (Le. excluding 'true' Apatelodidae). Often regarded as incertae sedis, the African genera Sabalia Walker and Spiramiopsis Hampson are definitely assigned to the Lemoniidae and Brahmaeidae respectively. Autapomorphies of these two families are recorded and discussed, as are those found to characterize the Sphingidae. Three subfamilies are tentatively recognized within the latter (Smerinthinae stat. rev., Sphinginae, Macroglossinae), five within the Eupterotidae (Hibrildinae, Tissanginae, Janinae, Panacelinae, Eupterotinae), and four within the Bombycidae s.lat. (Apatelodinae, Phiditiinae subfam. n., Prismostictinae [= Oberthueriinae, syn. rev.], Bombycinae). Three of these subfamilies are considered in a new sense, viz. the Panacelinae, Apatelodinae, and Bombycinae. Although the phylogeny of the Saturniidae is not fully taken into account in the present study, the composition of three saturniid subfamilies is critically examined (Oxyteninae, Cercophaninae, Ludiinae), and the Oxyteninae are viewed as the most 'primitive' member of the family.


2021 ◽  
Vol 8 ◽  
Author(s):  
Emily E. Hardin ◽  
Mariana M. P. B. Fuentes

While widely applied in fisheries science, acoustic telemetry remains an underutilized method in the field of marine turtle biotelemetry. However, with the ability to provide fine-scale spatial data (tens to hundreds of meters, depending on array setup and receiver range) at a low cost, acoustic telemetry presents an important tool for obtaining key information on marine turtle ecology. We present a comprehensive and systematic review acknowledging how acoustic telemetry has been used to advance the field of marine turtle ecology and conservation. We identify the extent of current studies and discuss common and novel research approaches while addressing specific limitations of acoustic telemetry. Forty-eight studies were reviewed, representing six of the seven marine turtle species and all life stages, with most individuals identified as juveniles (45%) and hatchlings (36%). Most studies (83%) focused on the spatial distribution of marine turtles, including estimating home ranges, investigating drivers of habitat use, and identifying horizontal movement patterns and vertical space use. Additionally, acoustic telemetry has been used to study hatchling dispersal and marine turtle exposure and response to threats, as well as to monitor physiological parameters. We identified that acoustic telemetry directly or indirectly informs 60% of the top questions and research priorities related to marine turtles identified by experts in the field. With an increase in acoustic telemetry receiver networks and collaborations across taxa, the applicability of acoustic telemetry is growing, not only for marine turtles but for a wide array of marine species. Although there are limitations that need to be considered at a site/project-level, acoustic telemetry is an important, low-cost technology able to address key questions related to marine turtle ecology that can aid in their conservation, and therefore should be considered by researchers as they develop their projects.


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