REPTILES

Testudines 341 species

Turtles: Testudines Joyce et al Pleurodira Cryptodira Testudines

Turtle synapomorphies Limb girdles internal to rib cage Lack teeth Loss/fusion of skull bones Anapsid skull Shell – dorsal carapace – ventral plastron

Turtle shell Carapace (dorsal shell) – Composed of bones Fused to ribs Fused to vertebrae Plastron (ventral shell) – Composed of 9 bones Bones covered by epidermal "scales"

Life with a shell Protection from predators Constrained morphology – Affects physiology, ecology, selective response Shell shape often reflects ecology ("ecomorphology") – Terrestrial: domed – Aquatic: flattened, streamlined Storage of calcium Breathing adaptations

Turtle respiration Ribs (shell) are rigid, so can't use costal muscles to breathe like other vertebrates Lungs are dorsal, attached to carapace Sheets of muscle attach internal organs to shell – One set of muscles pulls internal organs distally in body cavity (inspiration) – Other set pulls organs inwards and upwards towards lungs, forcing air out Some cutaneous, buccal respiration Cloacal breathing

1. Premaxilla 2. Prefrontal 3. Frontal 4. Postorbital 5. Parietal 6. Squamosal 7. Supraoccipital 1. Premaxilla 2. Maxilla 3. Vomer 4. Palatine 5. Zygomatic (jugal) 6. Postorbital 7. Quadratojugal 8. Quadrate 9. Squamosal 10. Supraoccipital 11.Parietal

Turtle Life History Carnivorous, Omnivorous, or Herbivorous Generally long-lived Internal fertilization All species oviparous – Nest in soil or sand Temperature dependent sex determination No parental care

Variation in turtles Skull structure Aquatic, terrestrial traits – Limbs – Shell Shell structure – Plastron hinged/rigid – Carapace Shape, extent Skin Omnivore/carnivore/ herbivore

Chelidae: Chelus fimbriatus 11 genera, 54 spp

Pelomedusidae: Pelomedusa subrufa 2 genera, 19 spp

Chelydridae: Chelydra serpentina 2 genera/spp

Emydidae: Terrapene carolina Emydidae: Trachemys scripta 12 genera, 50 spp

Chelonidae: Chelonia mydas 5 genera, 6 spp

Testudinidae: Gopherus berlandieri 11 genera, 58 spp

Trionychidae: Apalone spinifera 14 genera, 30 spp

Kinosternidae: Kinosternon flavescens 3 genera, 25 spp

Turtle phylogeny Gaffney and Meylan (1988) – Morphology; parsimony Shaffer et al. (1997) – mtDNA, morphology; parsimony Fujita et al. (2004) – nDNA; likelihood Krenz et al. (2005) – mtDNA, nDNA; parsimony, likelihood, Bayesian 2010 – Thomson and Shaffer (50 kb nDNA, mtDNA; parsimony; 'sparse supermatrix') – Barley et al. (10+ kb nDNA, mtDNA; likelihood, Bayesian) – Sterli (morphology, nDNA, mtDNA, fossil taxa; parsimony) 2015 – Crawford et al. Pleurodira Cryptodira

Barley et al.