XI. Creation Day Six
Animal Life on Land
Day Six celebrates the creation of land animals, and finally of Man, the crowning event of the entire creation narrative. The words "God said" and "made" indicate that the creation of the land animals is a new phase of the work of creating animals begun on Day Five, rather than a new departure. The movement of animals to land (and birds in the air) had to wait until the Ozone layer was fully in place, which happened around 400 million years ago (Ma), at about the same time that plants began to "green" the land on Day Three.
As with the plants in Day Three, and the sea creatures of Day Five, the animals mentioned are the most advanced land animalsXI.02 —from the highest, most developed body plan, the Craniata (or Vertebrata) which have a brain connected to a central spinal cord: the brain is enclosed in a skull that forms the head. The spine is also enclosed in a reticulated, bony or cartilaginous spinal column. The word "Chordate" emphasizes the central nerve cord which is enclosed in an articulated bony spine. The word "Craniata" emphasizes that the nervous system is protected by a cranium. These are the animals that have a (greater or lesser) ability to think, emote, and other characteristics that are, I believe, implied by the statement that they are "living souls" (translated here "living creatures").
Only general terms for the animals are mentioned and the terms used appear to refer to familiar categories of modern animals:
• The Behemah (the word is a transliteration of the Hebrew) appear to refer to grazing animals such as cattle and sheep—in the book of Job, the behemoth is probably the hippopotamus (a grazing animal).
• The Creeping Things (remesh) may refer to burrowing and ground animals, and
• The Beasts of the Earth (chayyath) may refer to wild animals -- carnivores?
The classes of vertebrate land animals are: amphibians (Class Amphibia)XI.05, reptiles (Class Reptilia)XI.06, mammals (Class Mammalia)XI.07, and birds (Class Aves)XI.08, and this is the order (lower strata to upper strata) in which the land animals first appear in the geological record. Of course, each of these classes involves a broad range of shapes and sizes.
Once again, the geological record fills in the narrative with an extensive description of how the creation of land animals proceeded. The kinds of animals changed over the geological ages in parallel with the changes in the climate and available food. The process was gradual and deliberate.
There were two annhilation events that strongly impacted animal life on land. The first, called the Permian–Triassic (P–Tr) extinction event or the Great Dying, occurred at the end of the Permian age, 252.28 Ma. In this event up to 96% of the marine species and 70% of land vertebrates went extinct [Wikipedia], as well as a mass extinction of insects. The second annhilation event is the Cretaceous–Paleogene extinction event (also called K-T extinction) at the end of the Cretaceous age, 66 Ma, perhaps best known as the time that the dinosaurs and all large mammals suddenly disappeared from the fossil record. An asteroid impact in the vicinity of the Yucatan Penninsula (Mexico) is generally accepted as the cause of this annhilation. About 75% of all species were wiped outXI.09.
The earliest land animals, the amphibians, lived near water—on shorelines, near streams and rivers, in lowland swamps and marshes. That is, of course, where the food was, because the plants of Day Three followed the same progression.
The major Classes of the phylum Craniata are:
Class Amphibia—Lungs and gills. Larval stage in water. four limbs. These were the first vertebrates to move to land. They inhabit shorelines of lakes, rivers, oceans. All have one stage of life in which they live in water. They first appeared in the mid-Devonian (about 380 Ma). They are often identified in the fossil record by tracks.
Carboniferous (325 Ma) Amphibian Tracks in MudXI.10
note the tail mark
Class Reptilia—(lungs; amniotic egg, internal fertilization. Lizards, dinosaurs). Mesosaur (280 Ma) is probably the earliest amniote. Recently a fossil dinosaur embryo was discovered, demonstrating that some of these dinosaurs gave live birthXI.11.
Lower Permian (280 Ma) - Uruguay
length of embryo about 1 cm.
Reptiles are able to live on dry land away from water for their entire life cycle. Some remarkable footprints of dinosaurs were found by the geologist Edward Hitchcock along the Connecticut River.XI.12
Jurassic (160 Ma) Dinosaur Tracks
Class Aves—Wings; feathers, warm-blooded. Birds and mammals are warm-blooded. All other vertebrates are cold-blooded. The Archaeopteryx is the earliest fossil showing feathers. It may be a dinosaur or a bird (some dinosaurs appear to have feather-like plumage. Birds have a remarkable innovation: light-weight bones. XI.13 The feathers are remarkable examples of sophisticated design, with interlocking that allows free flow of air in one direction, and binds the feathers together when moving in the other direction.
Late Jurassic (ca. 150 Ma)
Class Mammalia (mammary glands). Mammals are characterized by being warm-blooded, and possessing hair, three middle ear bones for balance and hearing, and mammary glands. Red blood cells (lacking a nucleus) and a 4-chambered heart are also characteristics. Many of the mammals most familiar to us first appear in the fossil record 50-25 Ma. The earliest to appear are the Marsupials (most of the development of the fetus occurs outside of the womb) followed by the Placentals (most of the development occurs in the womb).
[SHOW PIX OF MAMMALS??]
Mammals have dominated animal life since the K-T extinction event (66 Ma) which wiped out the dinosaurs and many other species, but left some small mammals.