Anders G. J. Rhodin

Molecular systematics, phylogeography, and the effects of pleistocene glaciation in the painted turtle (Chrysemys picta) complex

Abstract.— The painted turtle, Chrysemys picta, is currently recognized as a continentally distributed polytypic species, ranging across North America from southern Canada to extreme northern Mexico. We analyzed variation in the rapidly evolving mitochondrial control region (CR) in 241 turtles from 117 localities across this range to examine whether the painted turtle represents a continentally distributed species based on molecular analysis. We found strong support for the novel hypothesis that C. p. dorsalis is the sister group to all remaining Chrysemys, with the remaining Chrysemys falling into a single, extremely wide‐ranging and genetically undifferentiated species. Given our goal of an evolu‐tionarily accurate taxonomy, we propose that two evolutionary lineages be recognized as species within Chrysemys: C. dorsalis (Agassiz 1857) in the southern Mississippi drainage region, and C. picta (Schneider 1783) from the rest of the range of the genus. Neither molecular nor recent morphological analyses argue for the hybrid origin of C. p. marginata as previously proposed. Within C. picta, we find evidence of at least two independent range expansions into previously glaciated regions of North America, one into New England and the other into the upper Midwest. We further find evidence of a massive extinction/recolonization event across the Great Plains/Rocky Mountain region encompassing over half the continental United States. The timing and extent of this colonization is consistent with a recently proposed regional aridification as the Laurentide ice sheets receded approximately 14,000 years ago, and we tentatively propose this paleoclimatological event as a major factor shaping genetic variation in Chrysemys.

A Global Analysis of Tortoise and Freshwater Turtle Distributions with Identification of Priority Conservation Areas

Abstract There are currently ca. 317 recognized species of turtles and tortoises in the world. Of those that have been assessed on the IUCN Red List, 63% are considered threatened, and 10% are critically endangered, with ca. 42% of all known turtle species threatened. Without directed strategic conservation planning, a significant portion of turtle diversity could be lost over the next century. Toward that conservation effort, we compiled museum and literature occurrence records for all of the worlds tortoises and freshwater turtle species to determine their distributions and identify priority regions for conservation. We constructed projected range maps for each species by selecting geographic information system–defined hydrologic unit compartments (HUCs) with verified locality points, and then added HUCs that connected known point localities in the same watershed or physiographic region and that had similar habitats and elevations as the verified HUCs. We analyzed a total of 305 turtle species and assigned each to 1 of 7 geographic regions of the world. Patterns of global turtle species distributions were determined and regional areas of turtle species richness identified. In only 2 areas of the world did as many as 18 or 19 species occur together in individual HUCs. We then compared species distributions with existing global conservation strategies (GCSs) and established biodiversity priority areas. Presence of a species in a GCS was defined as ≥ 5% its range. Of the 34 biodiversity hotspots, 28 collectively contain the projected ranges of 192 turtle species, with 74 endemic; the 5 high-biodiversity wilderness areas contain 72 species, with 17 endemic; and 16 other wilderness areas contain 52 species, with 1 endemic. However, 116 turtle species have either < 50% of their ranges in existing GCSs (57 species) or do not occur in them at all (59 species, 19.3%), thus potentially leaving many tortoises and freshwater turtles without any regional GCS. For each of these 116 species we identify a priority Ecoregion for further conservation consideration, and we identify 3 new global Turtle Priority Areas for conservation based on aggregated Ecoregions. These are the Southeastern United States, Lower Gangetic Plain, and Coastal Australia Turtle Priority Areas.

Comparative Chondro-osseous Development and Growth of Marine Turtles

Longitudinal skeletal growth in appendicular long bones of Caretta caretta resembles the patterns in Pseudemys scripta and Carettochelys insculpta. A metaphyseal cone of cartilage becomes transiently isolated through the formation of a subphyseal plate of calcified cartilage which undergoes early peripheral vascular irruption and ossification. The noncalcified epiphyseal cartilage remains thin and avascular. Skeletal growth in Dermochelys coriacea is remarkably divergent from other living chelonians. Primary vascular irruption occurs into the noncalcified hypertrophied cartilage of the metaphysis with rapid extension of vascularity also into the non-hypertrophied epiphyseal cartilage. Endochondral ossification of the metaphysis advances contiguously from the diaphysis, a subphyseal calcified cartilage plate does not form, and there is no isolation of a metaphyseal cartilage cone. The noncalcified epiphyseal cartilage remains thick with transphyseal as well as perichondral vascularization through cartilage canals. The pattern in Dermochelys may be due to very rapid skeletal growth to a large body size. The giant Cretaceous Archelon ischyros has a similar skeletal vascular pattern, whereas the giant Tertiary Stupendemys geographicus resembles normal chelonians. In many respects, skeletal growth of Dermochelys resembles marine mammalian patterns.

Karyotypic Variation in the Genus Platemys (Testudines: Pleurodira)

Standard karyotypes are reported for all currently recognized members of the South American genus Platemys. Platemys platycephala (2n = 64) has a karyotype distinct from the other four members of the genus (P. macrocephala, 2n = 48; P. pallidipectoris, P. radiolata, P. spixii 2n = 50). The range in diploid numbers within this genus is greater than all other members of the suborder Pleurodira. Such karyotypic variability is particularly uncommon among closely related turtles and supports generic separation of P. platycephala from the remaining four species. These four have karyotypes similar to Australian chelids, and, with Chelus, may represent a group intermediate between Australian and the other South American forms. THE two families of living pleurodiran tur

Turtle Hotspots: An Analysis of the Occurrence of Tortoises and Freshwater Turtles in Biodiversity Hotspots, High-Biodiversity Wilderness Areas, and Turtle Priority Areas

Abstract We analyzed the taxon richness and endemism of tortoises and freshwater turtles in the world’s premier biodiversity conservation priority areas and countries with greatest turtle richness. Turtle hotspots include biodiversity hotspots (BHS), high-biodiversity wilderness areas (HBWA), and additional turtle priority areas (TPA) previously identified. We present taxon richness and endemism values for the 16 turtle hotspots with highest richness and endemicity. These 16 turtle hotspots together contain 262 species (83% of total), of which 149 (47%) are endemic to these areas combined, and 134 species (43%) are endemic to just a single priority area. At the terminal taxon (subspecies) level, these 16 areas harbor 342 taxa (79%), of which 210 (48%) are endemic to these combined areas, and 195 (45%) are endemic to a single priority area. These 16 BHS, HBWA, and TPA account for less than 24 million square kilometers, or 16.0% of planet Earth’s land surface, with an estimated 10.4 million square kilometers of original habitat remaining, or 7.0% of the planet’s land surface. Twenty-one countries are recorded to harbor 15 or more species of non-marine turtles, with the percentage of endemic species ranging from 0% to 88%. Collectively, these 21 countries are inhabited by 275 (87%) species and 352 (81%) taxa, of which 115 (37%) species and 175 (40%) taxa are endemic to just a single country. Identification of these conservation priority areas and countries should assist conservation of turtles worldwide by focusing on areas where the greatest number of species and taxa can be secured and where the authorities and institutions that exist hope to accomplish these goals.

A New Subspecies of the Snakeneck Turtle Chelodina mccordi from Timor-Leste (East Timor) (Testudines: Chelidae)

ABSTRACT A new subspecies of Chelodina mccordi is described from Timor-Leste (East Timor). The nominate subspecies Chelodina m. mccordi is endemic to the small island of Roti to the southwest of Timor. The new subspecies has a very limited distribution in the area of Lake Iralalaro in Lautém District near the eastern tip of Timor-Leste and is endemic to that nation. In some morphological characters, the new subspecies is intermediate between C. m. mccordi from Roti and Chelodina novaeguineae from the island of New Guinea, but, in supporting its subspecific taxonomic status, the new taxon shows more similarities to the nominate form than to C. novaeguineae. The nominate form C. m. mccordi on Roti Island was nearly extirpated by commercial trade in the recent past and has been listed as critically endangered in the IUCN Red List since 2000. Chelodina mccordi is the only species of the genus listed in CITES Appendix II. As a subspecies of C. mccordi, the new taxon from Timor-Leste is automatically included in CITES Appendix II, meaning that any international export of this new taxon to a CITES signatory country requires an export permit from the government of Timor-Leste. This legal requirement will hopefully spare the new subspecies from Timor-Leste the fate of the nominate subspecies from Roti Island, to be nearly driven onto the cusp of extinction through commercial trade shortly after its description as a new taxon.

Blood biochemistry and relations among Podocnemis turtles (pleurodira, pelomedusidae)

Agglutination, precipitation and electrophoresis of hemoglobin and serum point to a core of five Podocnemis species (P. erythrocephala, P. expansa, P. lewyana, P. unifilis and P. vogli), with a sixth species (P. sextuberculata) fringing this cluster. 1. 2. In addition, the data indicate that P. dumeriliana and P. madagascariensis not only are generically distinct from the other six species, but also are not closely related to each other. The name Peltocephalus Dumeril & Bibron, 1835, is available for Podocnemis dumeriliana, while Erymnochelys Baur, 1888, should be used for P. madagascariensis.

Biochemical Systematics and Evolution in the South American Turtle Genus Platemys (Pleurodira: Chelidae)

Phenetic and phylogenetic methods of analysis of allozymic data were used to determine relationships among members of the South American genus Platemys (P. pallidipectoris, P. spixii, P. macrocephala, P. radiolata, and P. platycephala). Two members of the related genus Phrynops (P. gibbus and P. rufipes) were used in the phylogenetic analysis to determine character state polarities. Comparison of the biochemical analyses to those from chromosomal and morphological data indicated a general concordance between the data sets and supports specific status for all five members of the Platemys group. Platemys platycephala appears to be the most divergent member of the genus.

Vision Sokatra Gasy—Madagascar Turtle Vision

Turtles on the Brink in Madagascar: Proceedings of Two Workshops on the Status, Conservation, and Biology of Malagasy Tortoises and Freshwater Turtles Christina M. Castellano, Anders G.J. Rhodin, Michael Ogle, Russell A. Mittermeier, Herilala Randriamahazo, Rick Hudson, and Richard E. Lewis, Eds. Chelonian Research Monographs (ISSN 1088-7105) No. 6, doi: 10.3854/crm.6.a05p37 •

Editorial Introduction Refocusing on Leatherbacks: Conservation Challenges and Signs of Success

The leatherback sea turtle (Dermochelys coriacea)has been called Mercury’s turtle since the Middle Ages(Rondelet 1554), because its teardrop body plan and ridgesresemble the shape and strings of Mercury’s instrument,the lyre (leut, luc, or luth in French, lau´d in Spanish). And,because Mercury was the winged Roman messenger god,leatherbacks should perhaps be considered winged mes-sengers themselves. Certainly, their graceful underwaterflight, as illustrated on our cover, makes them appearwinged as they glide through their blue watery oceanicrealm, but they are also messengers—the harbingers ofpelagic environmental change and threats occurring withintheir habitat. We would do well to heed their silentmessage, and this journal issue addresses many of theconcerns relating to their survival.Over a decade has passed since Chelonian Conser-vation and Biology published the initial special focus issueon the leatherback turtle (Vol. 2, No. 2, October 1996).This was the inaugural contribution in a series of 5 specialissues or sections that have focused on hawksbills, Kemp’sridleys, Blanding’s turtles, and gopherine tortoises. As thefirst journal to dedicate its pages exclusively to leather-backs, that issue contained 18 contributions that focusedon the biology and conservation of leatherbacks around theworld. Those papers provided a broad perspective for aspecies that was fast becoming the symbol for theimperiled state of sea turtles. Collectively, the journaladdressed many issues, but 2 papers that sounded thealarm on regional extinctions captured much of theattention. Chan and Liew (1996) chronicled the disap-pearance of leatherbacks at the once-remarkable Tereng-ganu rookery in Malaysia, and Spotila et al. (1996)presented the grim potential of extinction for the entirePacific Ocean. In addition to these sobering accounts,encouraging papers were presented on skeletochronology(Zug and Parham 1996) and chondro-osseous development(Rhodin et al. 1996, building on previous work by Rhodin1985) that demonstrated rapid growth and relatively earlymaturation by leatherbacks. Thus, despite the real threat ofextinction in the Pacific, data also suggested thatleatherbacks, because of their relatively shorter generationtimes, could potentially respond to conservation effortsmore quickly than many of the hard-shelled cheloniid seaturtles.Since the first special focus issue, the leatherback’sstatus in the IUCN Red List has been upgraded fromendangered to critically endangered because of a globaldecline in nesting frequency (Sarti-Marti´nez 2000). Yet, ascaptured in the pages of the first special focus issue, therewere largely different nesting trends in the Atlantic andPacific. Whereas most, if not all, known Pacific nestingpopulations had experienced precipitous declines duringthe previous decades (Chan and Liew 1996, Spotila et al.1996), many rookeries in or near the Atlantic had beenstable or increasing (e.g., Boulon et al. 1996; Girondot andFretey 1996; Hughes 1996). Since then, it has becomeapparent that this trend continues (Spotila et al. 2000;Reina et al. 2002; Eckert and Kerr Bjorkland 2004; Duttonet al. 2005), and, based on the 2006 state of the world’sturtles report (Mast et al. 2006), annual leatherback nestingnumbers are substantially greater in the Atlantic than in thePacific.The burning question is: why are the 2 ocean basinpopulations behaving so differently? Perhaps this disparityresults from marked differences in fisheries by-catchmortality and/or harvest rates between the 2 ocean basins.We know that marine fisheries have had major impacts onleatherbacks (Eckert and Sarti 1997; Lewison et al. 2004;James et al. 2005; Carranza et al. 2006), but it is debatablewhether by-catch rates are sufficiently different to result inthe observed regional trends. Egg and female harvest mayalso contribute to differences; like fisheries, these areubiquitous threats (Sarti 2000; Kaplan 2005), but again,are they so different in the Atlantic vs. the Pacific? Othershave suggested that the responsible factors may be lowerreproductive output and hatching success and longer adultfemale remigration intervals in the Pacific vs. the Atlantic(Bell et al. 2003; Wallace et al. 2006; Saba et al. 2007).Indeed, the ocean basin dichotomy has been the focus of atleast 2 sea turtle expert working groups (NOAA TurtleExpert Working Group; Pacific-Atlantic Sea TurtleAssessment Workshop-PASTA, Lutcavage et al. 2006).The reality, however, is that we still do not have a smokinggun fully explaining the regional patterns, and it is clear