Atheism
- Locked due to inactivity on Aug 4, '16 4:13pm
Thread Topic: Atheism
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wow christians really do beive that their god is the only one that exsist
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More from Talk Origins...
Transition from amphibians to amniotes (first reptiles)
The major functional difference between the ancient, large amphibians and the first little reptiles is the amniotic egg. Additional differences include stronger legs and girdles, different vertebrae, and stronger jaw muscles. For more info, see Carroll (1988) and Gauthier et al. (in Benton, 1988)
* Proterogyrinus or another early anthracosaur (late Mississippian) -- Classic labyrinthodont-amphibian skull and teeth, but with reptilian vertebrae, pelvis, humerus, and digits. Still has fish skull hinge. Amphibian ankle. 5-toed hand and a 2-3-4-5-3 (almost reptilian) phalangeal count.
* Limnoscelis, Tseajaia (late Carboniferous) -- Amphibians apparently derived from the early anthracosaurs, but with additional reptilian features: structure of braincase, reptilian jaw muscle, expanded neural arches.
* Hylonomus, Paleothyris (early Pennsylvanian) -- These are protorothyrids, very early cotylosaurs (primitive reptiles). They were quite little, lizard-sized animals with amphibian-like skulls (amphibian pineal opening, dermal bone, etc.), shoulder, pelvis, & limbs, and intermediate teeth and vertebrae. Rest of skeleton reptilian, with reptilian jaw muscle, no palatal fangs, and spool-shaped vertebral centra. Probably no eardrum yet. Many of these new "reptilian" features are also seen in little amphibians (which also sometimes have direct-developing eggs laid on land), so perhaps these features just came along with the small body size of the first reptiles.
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...I don't think I'll reply to this until I fully flip through my friend's bible (which I borrowed even though I'm atheist)
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And in preparation for the reptile and mammal transitions...
# Early Reptiles vs Mammals
1 No fenestrae in skull | Massive fenestra exposes all of braincase
2 Braincase attached loosely | Braincase attached firmly to skull
3 No secondary palate | Complete bony secondary palate
4 Undifferentiated dentition | Incisors, canines, premolars, molars
5 Cheek teeth uncrowned points | Cheek teeth (PM & M) crowned & cusped
6 Teeth replaced continuously | Teeth replaced once at most
7 Teeth with single root | Molars double-rooted
8 Jaw joint quadrate-articular | Jaw joint dentary-squamosal (*)
9 Lower jaw of several bones | Lower jaw of dentary bone only
10 Single ear bone (stapes) | Three ear bones (stapes, incus, malleus)
11 Joined external nares | Separate external nares
12 Single occipital condyle | Double occipital condyle
13 Long cervical ribs | Cervical ribs tiny, fused to vertebrae
14 Lumbar region with ribs | Lumbar region rib-free
15 No diaphragm | Diaphragm
16 Limbs sprawled out from body | Limbs under body
17 Scapula simple | Scapula with big spine for muscles
18 Pelvic bones unfused | Pelvis fused
19 Two sacral (hip) vertebrae | Three or more sacral vertebrae
20 Toe bone #'s 2-3-4-5-4 | Toe bones 2-3-3-3-3
21 Body temperature variable | Body temperature constant
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# Haptodus (late Pennsylvanian) -- One of the first known sphenacodonts, showing the initiation of sphenacodont features while retaining many primitive features of the ophiacodonts. Occiput still more strongly attached to the braincase. Teeth become size-differentiated, with biggest teeth in canine region and fewer teeth overall. Stronger jaw muscles. Vertebrae parts & joints more mammalian. Neural spines on vertebrae longer. Hip strengthened by fusing to three sacral vertebrae instead of just two. Limbs very well developed.
# Dimetrodon, Sphenacodon or a similar sphenacodont (late Pennsylvanian to early Permian, 270 Ma) -- More advanced pelycosaurs, clearly closely related to the first therapsids (next). Dimetrodon is almost definitely a "cousin" and not a direct ancestor, but as it is known from very complete fossils, it's a good model for sphenacodont anatomy. Medium-sized fenestra. Teeth further differentiated, with small incisors, two huge deep- rooted upper canines on each side, followed by smaller cheek teeth, all replaced continuously. Fully reptilian jaw hinge. Lower jaw bone made of multiple bones & with first signs of a bony prong later involved in the eardrum, but there was no eardrum yet, so these reptiles could only hear ground-borne vibrations (they did have a reptilian middle ear). Vertebrae had still longer neural spines (spectacularly so in Dimetrodon, which had a sail), and longer transverse spines for stronger locomotion muscles.
# Biarmosuchia (late Permian) -- A therocephalian -- one of the earliest, most primitive therapsids. Several primitive, sphenacodontid features retained: jaw muscles inside the skull, platelike occiput, palatal teeth. New features: Temporal fenestra further enlarged, occupying virtually all of the cheek, with the supratemporal bone completely gone. Occipital plate slanted slightly backwards rather than forwards as in pelycosaurs, and attached still more strongly to the braincase. Upper jaw bone (maxillary) expanded to separate lacrymal from nasal bones, intermediate between early reptiles and later mammals. Still no secondary palate, but the vomer bones of the palate developed a backward extension below the palatine bones. This is the first step toward a secondary palate, and with exactly the same pattern seen in cynodonts. Canine teeth larger, dominating the dentition. Variable tooth replacement: some therocephalians (e.g Scylacosaurus) had just one canine, like mammals, and stopped replacing the canine after reaching adult size. Jaw hinge more mammalian in position and shape, jaw musculature stronger (especially the mammalian jaw muscle). The amphibian-like hinged upper jaw finally became immovable. Vertebrae still sphenacodontid-like. Radical alteration in the method of locomotion, with a much more mobile forelimb, more upright hindlimb, & more mammalian femur & pelvis. Primitive sphenacodontid humerus. The toes were approaching equal length, as in mammals, with #toe bones varying from reptilian to mammalian. The neck & tail vertebrae became distinctly different from trunk vertebrae. Probably had an eardrum in the lower jaw, by the jaw hinge.
Thrinaxodon (early Triassic) -- A more advanced "galesaurid" cynodont. Further development of several of the cynodont features seen already. Temporal fenestra still larger, larger jaw muscle attachments. Bony secondary palate almost complete. Functional division of teeth: incisors (four uppers and three lowers), canines, and then 7-9 cheek teeth with cusps for chewing. The cheek teeth were all alike, though (no premolars & molars), did not occlude together, were all single- rooted, and were replaced throughout life in alternate waves. Dentary still larger, with the little quadrate and articular bones were loosely attached. The stapes now touched the inner side of the quadrate. First sign of the mammalian jaw hinge, a ligamentous connection between the lower jaw and the squamosal bone of the skull. The occipital condyle is now two slightly separated surfaces, though not separated as far as the mammalian double condyles. Vertebral connections more mammalian, and lumbar ribs reduced. Scapula shows development of a new mammalian shoulder muscle. Ilium increased again, and all four legs fully upright, not sprawling. Tail short, as is necessary for agile quadrupedal locomotion. The whole locomotion was more agile. Number of toe bones is 2.3.4.4.3, intermediate between reptile number (2.3.4.5.4) and mammalian (2.3.3.3.3), and the "extra" toe bones were tiny. Nearly complete skeletons of these animals have been found curled up - a possible reaction to conserve heat, indicating possible endothermy? Adults and juveniles have been found together, possibly a sign of parental care. The specialization of the lumbar area (e.g. reduction of ribs) is indicative of the presence of a diaphragm, needed for higher O2 intake and homeothermy. NOTE on hearing: The eardrum had developed in the only place available for it -- the lower jaw, right near the jaw hinge, supported by a wide prong (reflected lamina) of the angular bone. These animals could now hear airborne sound, transmitted through the eardrum to two small lower jaw bones, the articular and the quadrate, which contacted the stapes in the skull, which contacted the cochlea. Rather a roundabout system and sensitive to low-frequency sound only, but better than no eardrum at all! Cynodonts developed quite loose quadrates and articulars that could vibrate freely for sound transmittal while still functioning as a jaw joint, strengthened by the mammalian jaw joint right next to it. All early mammals from the Lower Jurassic have this low-frequency ear and a double jaw joint. By the middle Jurassic, mammals lost the reptilian joint (though it still occurs briefly in embryos) and the two bones moved into the nearby middle ear, became smaller, and became much more sensitive to high-frequency sounds.
* Oligokyphus, Kayentatherium (early Jurassic, 208 Ma) -- These are tritylodontids, an advanced cynodont group. Face more mammalian, with changes around eyesocket and cheekbone. Full bony secondary palate. Alternate tooth replacement with double-rooted cheek teeth, but without mammalian-style tooth occlusion (which some earlier cynodonts already had). Skeleton strikingly like egg- laying mammals (monotremes). Double jaw joint. More flexible neck, with mammalian atlas & axis and double occipital condyle. Tail vertebrae simpler, like mammals. Scapula is now substantially mammalian, and the forelimb is carried directly under the body. Various changes in the pelvis bones and hind limb muscles; this animal's limb musculature and locomotion were virtually fully mammalian. Probably cousin fossils (?), with Oligokyphus being more primitive than Kayentatherium. Thought to have diverged from the trithelodontids during that gap in the late Triassic. There is disagreement about whether the tritylodontids were ancestral to mammals (presumably during the late Triassic gap) or whether they are a specialized offshoot group not directly ancestral to mammals.
* Pachygenelus, Diarthrognathus (earliest Jurassic, 209 Ma) -- These are trithelodontids, a slightly different advanced cynodont group. New discoveries (Shubin et al., 1991) show that these animals are very close to the ancestry of mammals. Inflation of nasal cavity, establishment of Eustachian tubes between ear and pharynx, loss of postorbital bar. Alternate replacement of mostly single- rooted teeth. This group also began to develop double tooth roots -- in Pachygenelus the single root of the cheek teeth begins to split in two at the base. Pachygenelus also has mammalian tooth enamel, and mammalian tooth occlusion. Double jaw joint, with the second joint now a dentary-squamosal (instead of surangular), fully mammalian. Incipient dentary condyle. Reptilian jaw joint still present but functioning almost entirely in hearing -
Dinosaurs to Birds
# Archeopteryx lithographica (Late Jurassic, 150 Ma) -- The several known specimes of this deservedly famous fossil show a mosaic of reptilian and avian features, with the reptilian features predominating. The skull and skeleton are basically reptilian (skull, teeth, vertebrae, sternum, ribs, pelvis, tail, digits, claws, generally unfused bones). Bird traits are limited to an avian furcula (wishbone, for attachment of flight muscles; recall that at least some dinosaurs had this too), modified forelimbs, and -- the real kicker -- unmistakable lift-producing flight feathers. Archeopteryx could probably flap from tree to tree, but couldn't take off from the ground, since it lacked a keeled breastbone for large flight muscles, and had a weak shoulder compared to modern birds. May not have been the direct ancestor of modern birds. (Wellnhofer, 1993)
# Sinornis santensis ("Chinese bird", early Cretaceous, 138 Ma) -- A recently found little primitive bird. Bird traits: short trunk, claws on the toes, flight-specialized shoulders, stronger flight- feather bones, tightly folding wrist, short hand. (These traits make it a much better flier than Archeopteryx.) Reptilian traits: teeth, stomach ribs, unfused hand bones, reptilian-shaped unfused pelvis. (These remaining reptilian traits wouldn't have interfered with flight.) Intermediate traits: metatarsals partially fused, medium-sized sternal keel, medium-length tail (8 vertebrae) with fused pygostyle at the tip. (Sereno & Rao, 1992).
# "Las Hoyas bird" or "Spanish bird" [not yet named; early Cretaceous, 131 Ma) -- Another recently found "little forest flier". It still has reptilian pelvis & legs, with bird-like shoulder. Tail is medium-length with a fused tip. A fossil down feather was found with the Las Hoyas bird, indicating homeothermy. (Sanz et al., 1992)
# Ambiortus dementjevi (early Cretaceous, 125 Ma) -- The third known "little forest flier", found in 1985. Very fragmentary fossil.
# Hesperornis, Ichthyornis, and other Cretaceous diving birds -- This line of birds became specialized for diving, like modern cormorants. As they lived along saltwater coasts, there are many fossils known. Skeleton further modified for flight (fusion of pelvis bones, fusion of hand bones, short & fused tail). Still had true socketed teeth, a reptilian trait. -
Whoa Hammy I think we get it, I'm getting a migraine...
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hey carri
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My nickname is Hammy>:(
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Yush, I believe I have proven my point.(: Plus, I'm too lazy to go back and get more.
Fun fact: Velociraptor had feathers. I mean, who can say there are no transitional species when there were bloody dinosaurs wandering around in feathers? -
i was talking to carri
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not Biance
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im not sure what to believe, and i will probably never know, until i die. so that part of the reason that im not baptised yet
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LOL I can't tell whether I'm athiest or Satanist.... and hey bunnie
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hi carri, i wont try to change your opinnion on God or anything, because its not up to me to decide
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