First Draft Prepared September, 2010


       

In Celebration of Psalm Nineteen:
God's handiwork in Creation

Chapter 9
The Creation of Animals

UNDER CONSTRUCTION

NOTE:  Chapters 9-11 will be reorganized in the final version.



The Earth's Fossil Record
One of the most remarkable examples of the Silent Speech is the fossil record. As Baron Cuvier remarked in 1822:

"It is to fossils alone that must be attributed the birth of the theory of the earth; that, without them we could never have surmised that there were successive epochs in the formation of the globe, and a series of different operations. Indeed, they alone prove that the globe has not always had the same crust, by the certainty of the fact that they must have existed at the surface before they were buried in the depths where they are now found. It is only by analogy that we extend to primitive formations that conclusion which fossils enable us definitively to ascribe to secondary formations; and if there were only formations without fossils, no one could prove that these formations were not simultaneously produced. Again, it is to fossils, small as has been our acquaintance with them, that we owe the little knowledge we have attained respecting the nature of the revolutions of the globe. They have taught us, that the layers which comprise them have been undisturbedly deposited in a liquid; that their alterations have corresponded with those of the liquid; that their exposure was occasioned by the removal of this liquid; that these exposures have taken place more than once. None of these facts could have been decided on without these fossils."
Baron Georges Cuvier, A Discourse on the Revolutions of the Surface of the Globe, page 36.
See also David C. Bossard,  The Stones Cry Out, IBRI Research Report #57 (2006)l

The existence of fossils in and by themselves, carefully preserved by the Creator over hundreds of millions -- even billions --  of years, have led to the certain understanding that the Earth is exceedingly ancient, and this fact was known decades before modern dating techniques were known. Only these fossils have made it possible to prove that the same uniquely identifiable plant and animal species co-existed in time all over the habitable parts of the earth.

Since that early recognition of the importance of fossils, modern advances in science have taken the insights provided by fossils to an astonishing degree, leading to finer and finer calibration of the details of how life developed on Earth. The discovery of uncounted numbers of microscopic fossils, the refinement of multiple, overlapping radioactive dating techniques, the uncovering of rare but abundantly prolific remains of both hard and soft tissues of a broad range of species from the very beginning of multicellular life adds to the marvels of insight provided by these fossils.

This speech from the fossil record has revealed itself and made possible an understanding Earth's history in the distant past. This silent speech has proclaimed God's glory and handiwork for over 300 years, and the fruitful results contnue to arrive in an increasing crescendo right up to the present time.


The Geologic timescale. The fossil record of visible plants and animals begins in the Cambrian Era, nominally dated to around 540 Ma[FOOTNOTE: the actual beginning of the Cambrian Era is determined by the International Subcommission on Cambrian Stratigraphy. In 1991 they set the Cambrian boundary at the first appearance of fossil burrows known as Trichophycus pedum, that were obviously made by a complex animal, probably an arthropod, dated to 590 Ma. Since that time the date has been moved to a later time; it is still under discussion. See the lecture, David C. Bossard Abundant Life].

Geologic Clock from Wikipedia
Figure 1
The Geologic Clock


In the time between the creation of the first life (around 3,900 Ma) and the appearance of visible, multicellular life in the Cambrian Era, a principle task of life as it then existed was to fill the globe with organic nutrients in preparation for the future creation of complex life (another task was to create an oxygen atmosphere). These organic nutrients include, in particular, abundant amounts of fixed nitrogen, an essential component of dna and virtually every other molecule that participates in the central dogma of life -- the nucleotides of rna and dna, and the proteins' backbone amino acids[FOOTNOTE: By definition all amino acids include a nitrogen-containing amino group NH2]. Fixed nitrogen was scarce throughout the first few billion years of Earth's existence, and had to be manufactured from atmospheric nitrogen gas by the difficult, slow, energy intensive process of nitrogen fixing. Nitrogen fixing is done by bacteria that specialize in that one task. They first make the complex nitrogenase molecule, and then concentrate on the single task of fixing nitrogen one molecule at a time -- a process that takes about 1.2 seconds per nitrogen atom
. This task is so all-demanding that the nitrogen-fixing cells require food and energy (in the form of ATP) provided by other cells: most nitrogen-fixing bacteria cannot live independent lives.

The more complex the life form, the less it can afford to take the time or energy to create its own food. Thus there has to be readily available organic food -- amino acids, nucleotides, sugars, etc. -- so that the complex species could concentrate their energies on more advanced tasks[FOOTNOTE: Until the recent manufacture of inorganic ammonia by the Haber process, the only significant source of fixed nitrogen was organic food. Small amounts of inorganic nitrogen are produced by lightning, but this is transitory and not reliable. It is difficult to estimate the amount produced in ancient times, but over the past billion years or so, the percentage of fixed nitrogen produced by inorganic means is estimated to be under ??%??CHECK??]. This filling of the earth took a long time, and this is the primary reason why the first appearance of visible plants and animals in the Cambrian explosion around 540 Ma was over three billion years after the first living cell appeared on earth.

The first plants and animals lived in water. They fed on dissolved nutrients, microbes, colonies of algae and plankton, and of course on other small plants and animals. Plants are often called "autotrophic" meaning their principal food is inorganic, but that is a misnomer, because all plants have to get fixed nitrogen from organic sources (legumes get fixed nitrogen from symbiotic nitrogen-fixing bacteria attached to their roots). Even nitrogen-fixing bacteria must depend on other bacteria to supply organic food.

True multi-cellular species arose somewhere between 1000 Ma and 550 Ma. At the beginning they had no skeletons or other hard parts, so the earliest fossils are limited to burrows of worm-like animals, compressed impressions or mats of plants, and other indirect evidence. One exception to this rule is the rare appearance of soft-body fossils in the Burgess Shale and Cheng-Jiang Cambrian sites, which were preserved under oxygen-free conditions.

All plants and animals at this stage lived in the oceans. The dry land was kept relatively sterile at this time because of the high-energy "hard" cosmic and solar rays. The first colonizers of dry land (400-450 Ma) were bacteria which could hide from direct sunlight -- in soils or under rocks.

Animal fossils appear suddenly in the Cambrian Era, nominally 542 to 500 Ma with the nearly-simultaneous appearance of most if not all of the known animal body plans (phyla). With time, some early phyla disappear, but no new animal phylum arises after the Cambrian era, with the possible exception of Bryozoa = "moss animals" which first appear in the fossil record in the early Ordovician Era, about 480 Ma -- but possibly soft-bodied bryozoa may have existed in the Cambrian Era. Plant phyla have a more variable fossil record, many appearing much later, because of the problem of land-colonialization.

One of the first and most complex animals to appear is the trilobite, an arthropod (joint-footed appendages), which by any reckoning must be viewed as a complex and morphologically advanced creature. This very complexity and sudden appearance suggests that the true origin was earlier than the fossil record indicates[FOOTNOTE: Some paleobiologists argue that the real innovation in the Cambrian era was hard skeletal parts which the fossil record preserves; prior to this innovation, the same species existed in soft bodies that were not preserved. Until positive evidence arises to support this (such as soft-bodied trilobites) this seems to be a case of special pleading in the absence of evidence. Regarding this, the Cambrian Factsheet (Discovery Institute) remarks: "Some scientists have suggested that fossil ancestors for the animal phyla are missing not because the rocks have been deformed or eroded, but because animals before the Cambrian lacked hard parts, and thus never fossilized in the first place. According to this hypothesis, the Cambrian explosion merely represents the sudden appearance of shells and skeletons in animals that had evolved long before. The fossil evidence, however, does not support this hypothesis.].

Coral reefs also appear at this time, the by-product of early soft-bodied cnidarians who secrete calcium that forms a hard habitat in which the coral individuals dwell (somewhat like the much earlier stromatolyte-forming cyanobacteria). Since the cnidarians are basically soft-bodied, it is not difficult to imagine that the coral ancestors were soft-bodied creatures that did not secrete calcium.

Fossil
radiolaria and foraminifera also appear at this time. These are single-celled animals that build a hard skeleton and needle-like spicules [FIGURE: radiolaria and forams].

In general, the hard parts of animals are calcium (calcium carbonate or calcium phosphate) and silica (silicon dioxide -- quartz and sand).

Because of the soft bodies, the early plant record is less abundant, and plants as we commonly think of them do not flourish in the fossil record until they begin to appear on land, around 350 Ma. By this time, an ozone layer in the outer atmosphere has built up to the point that it can filter out the most harmful hard cosmic rays, which allows both plants and animals to grow on dry land. Because of this late appearance in the fossil record, we will discuss animal creation first, even though animals are admittedly much more complex than plants.

Many-Celled Colonies. As we noted in an earlier chapter, evidence of single-celled cyanobacteria goes back to nearly the earliest stages of the Earth, when it was first cool enough to have oceans and living cells. These, too, left a fossil record in the form of stromatolytes which were formed by calcium excretions of the bacteria. The early cyanobacteria formed stromatolyte colonies made up of single-celled bacteria, in which the bacteria specialize in various ways that benefit the colony as a whole. Specialized forms of cyanobacteria include heterocysts which fix nitrogen, and akinetes, which  are a dormant, protective form that can survive harsh conditions. In addition, the layers of cyanobacteria that form the stromatolytes have various specialized layers [DISCUSS].

All single-celled eukaryotic species live in water, or at least in moist environments (soils or tissues). Lynn Margulis places these species in the kingdom Protoctista. They are sometimes called protists - protophyta (plant-like) and protozoa (animal-like)[FOOTNOTE: See Margulis, Kingdoms and Domains, p.122]. Many of the species have complex life-cycles that include colonial phases.

The life cycle of the slime molds (Margulis' phylum Rhizopoda, Pr-2) gives a fascinating example of something that seems half-way  between a colony and a multi-celled animal (Figure 1)[FOOTNOTE:The Rhizopod D. discoideum, ibid., Fig. F, p. 137 (also available here.). Ongoing reserach on this species is proceeding in a number of areas: cellular differentiation, signaling, programmed cell death, etc. because of its short life cycle (8-10 hrs).  The DNA has been completely sequenced.]. It is independent single-celled amoebas at one stage. At another stage the amoebas swarm to form a "slug". The slug looks and moves like a multi-cellular animal -- including a slimy cellulose "skin", but in fact each of the component amoebas retains its individual identity (CHECK). In the reproductive stage the "slug" grows into a fruiting body -- a stalk with a round cap that bursts into a shower of spores that produce the next generation amoebas. At this point some of the original amoebas undergo programmed deaths to form the stalks and other specialized portions of the fruiting body. In the aggregated stages, the individual amoebas appear to use chemical signalling to initiate the various stages in the life cycle and coordinate the movements of the aggregation.

D discoideum life cycle
Figure 2
Slime Mold Life Cycle


World Land Map during the Cambrian Era.

The worldwide distribution of Cambrian fossils carries with it implications for how the continental landmass was configured during that Era (see Figures 3a-3c).

Map-Early Cambrian Landmass
Figure 3a
Early Cambrian Landmass
544-511 Ma
Map Mid-Cambrian Landmass
Figure 3b
Mid-Cambrian Landmass
511-497 Ma
Map-Late Cambrian Landmass
Figure 3c
Late Cambrian Landmass
497-482 Ma

Note that over this time the North American landmass moved from mid-Southern latitudes to equatorial latitudes. Note also the proximity of the future (emerging) Siberia, Greenland and North America, and the separation of these from South China (the location of the ChengJiang Ediacaran and Cambrian fossil beds).


Continental Formation and Tectonic Movement

The Silent Speech of Psalm 19 includes an extensive record of how the Earth's landmass changed over the entire fossil record of life on earth. The description of this tectonic movement combines  a number of scientific disciplines, and involves extensive information preserved in a continuous record for over 500 million years. The website Dinodata shows this in one of the best collection of Early History Maps available on the Internet, The fact that scientists can form these maps of the distant past is a remarkable example of how God has invested his Creation with a silent speech that proclaims his glory and handiwork.


fractal


Many-Celled Plants and Animals. What is the difference between a colony of individual single-celled species and a multi-cellular plant or animal? Presumably the individual cells of multi-celled species cannot enjoy an independent existence. This situation was already seen in the heterocysts of cyanobacteria, which depend on sustenance from adjacent cyanobacteria. The cyanobacteria form heterocysts when they are facing a nitrogen deficiency. The nitrogen production is destroyed by oxygen which is a byproduct of photosynthesis, and so the heterocysts get the ATP and sugars produced by photosynthesis from adjacent cells. See also the Wikipedia article on the Evolution of multicellularity.

Inventions Associated with the Appearance of Plants and Animals.

oxygen metabolism -- requires circulation -- either osmosis or a circ syst. sexual reproduction.  Chromosomes --

The Difference between Plants and Animals.

Plant body plans are algorithmic; animal body plans are topological (with algorithmic components)[FOOTNOTE: In Medicine, "Topology" refers to "The anatomical structure of a specific area or part of the body." from Answers.com)]. And therein lies all the difference.

Algorithmic body plans. An algorithmic body plan is rule-based with random variations superimposed. The prototype for an algorithmic plan is the "knit one, perl two" rule for knitting. The body plans for plants are typically algorithmic and result in the haphazard appearance of tree branches, leaf veins. It is not that they have no systematic plan, it is that the plan is algorithmic: put out a new branch in a random direction according to an established rule for that species. The result is roughly symmetric in the large but apparently haphazard in the small. Tree shapes and leaf shapes follow a general pattern that is species-dependent.

Figure 3 shows an example of algorithmic growth of leaf veins. Algorithms control the (random) placement of the main, secondary and tertiary branching. In this instance, all of the branching occurs in the plane of the leaf, but the spacing and orientation of the veins is clearly random but follows definite rules.

Leaf Venation
Figure 3
Leaf Venation
An Example of Algorithmic Growth
[SUBSTITUTE MY OWN PIX]

Figure 4 shows an example of tree branching. Again note the algorithmic placement of branches, which in this case occurs in three-dimensions. The placement/growth algorithm is obviously influenced by access to sunlight. Root growth also follows a similar branching algorithm, influenced by access to water and nutrients.

Tree Branching
Figure 4
Tree Branching
[SUBSTITUTE MY OWN PIX]

Plant embryos immediately (??) produce cells that form a cell wall. These do not move relative to one another. Growth occurs by cell division interior to the cell wall (??). See also the Wikipedia article on the evolution of leaves.

Topological body plans
. Topological body plans take account of cell location within the body. In effect, they build the body according to a 3-dimensional map, and distinguish body location: anterior/posterior (head/tail), left/right, and dorsal/
ventral (front/back), Topological plans can result in left-right body symmetry or anti-symmetry,  body segmentation (head, thorax, etc.), organ placement, and other complex details that algorithmic plans cannot achieve. Animal body plans are topological.

The
body plan of an embryonic animal first shows up in the blastula (a hollow sphere), which is entirely formed of undifferentiated stem cells. All animals (and only animals) pass through a blastula stage during their embryonic development[FOOTNOTE: Margulis, p.233]. From this stage on the stem cells immediately begin to differentiate based on position and orientation in the embryo, and locate the (future) head, legs, intestine, nerve system, etc. Thus the topological body plan is fundamental to all animals, in contrast to plants.

The body plan is controlled by a package of genes called the homeobox (hox) genes. The composition of this gene package varies by phylum (??). The hox genes control gene expression, and the parameters for this gene expression are stored in non-coding portions of the dna (i.e. these dna do not code for genes). All hox genes are headed by a dna marker of 183 base pairs called the homeobox and the corresponding 61 amino acid section of the hox proteins is called the homeodomain. This uniquely identifies all hox genes, and is essentially the same over a large swath of animal phyla "from fruitflies to man." Hox genes across the animal species forms the subject matter of evolutionary developmental biology (evo-devo).

The implementation of the body plan permits variation in development within closely defined limits. This variation is called phenotype plasticity. This variation is in addition to changes that result from radiation damage or various types of copying errors that may slip through the cell's error-checking machinery.  Apparently a mechanism exists to preserve some of these variations, so that it can (occasionally) be passed on to future generations -- probably within the non-coding portions of the dna.

The Cambrian Explosion

The Animal kingdom appears suddenly in the fossil record over 600 My ago, in what has come to be called the Cambrian explosion. The boundary that defines the start of the Cambrian age is the appearance of fossil burrows that were obviously made by a complex animal, probably an arthropod—the name means “jointed feet”, think lobster. We will meet trilobites, a kind of arthropod, in a minute.
Animals differ from plants in that they have a much more elaborate body plan that is built into the embryonic development. This plan is incorporated into the homeobox or "hox" genes and expression or development genes. The various animal phyla differ in the organization of these genes, and the resulting complexity of the species.

Cambrian Mollusc bivalve
Figure ??
Trichophycus fossil burrows
that define the start of the Cambrian age


The beginning of the Cambrian age is currently set at about 590 My ago, and marks the start of the “Phanerozoic Era”, which means “visible animals”, ones that are visible to the unaided eye[FOOTNOTE: In 1991 the International Subcommission on Cambrian Stratigraphy officially set the Cambrian boundary at the first appearance of these fossils. See http://www.uni-wuerzburg.de/palaeontologie/Stuff/casu8.htm.].

The irony, from the perspective of natural evolution, is that all of the basic animal body plans appear almost simultaneously within about a 10 My span of time about 530 Ma.  Recent work on development genes indicates that at this time, a number of basic gene packages appear which were used over and over in many combinations during the subsequent development of animal life.  For example, there are development gene packages to control the development of appendages, of eyes, of the nervous system. These same packages are used repeatedly in different configurations over the next 500My.

cambrian fossils.  trilobite, pikaia, arthropods, brachiopods, eocrinoids, corals shellfish,
many become much more elaborately and characteristically  formed in ordovician (e.g. starfish) but the phylum is clearly present.

The Timeline of Evolution

haploid/diploid  stages of life. In sexual animals: diploid is normal. egg and sperm are haploid, and join at fertilization to form a diploid.

haploid = only half there.

With the creation of the eukaryotic cell, multi-cellular plants and animals can be made.

Remarkable living fossil from the Cambrian Era:  Monoplacophorans -- ancestral to later mollusc classes. 1952 Galathea expedition: 10 living species of Neopilina galathea.

polyplacophorans http://animaldiversity.ummz.umich.edu/site/accounts/information/Polyplacophora.html

PR-3 - Granuloreticulosa (Foraminifera).   First appear Early Cambrian, about 542 Ma.

See the Foraminifera gallery developed and maintained by Michael Hesemann.
 
PR-28 - Chlorophyta (green algae).

Margaretia-dorus green algae
Figure ??
Middle Cambrian Green Algae
Margaretia dorus
Wheeler Shale, Millard County, Utah
The Virtual Fossil Museum



PR-31 - Actinopoda (Radiolaria).

See also Haeckels HMS Challenger report on Radiolaria
[Some stunning pics from Cambrian are in the Lyell collection (Geological Society, London). However this is a pay-per-view.]

PR-32 - Gamophyta (green algae).

PR-33 - Rhodophyta (red algae). 

A-3 Phylum Porifera. Early Cambrian fossils include a short-lived (about 10My) but prolific blossoming of a sponge Archaeocyathans. They are the first reef-building animals, conical shaped with a calcium carbonate (calcite) shell -- similar in overall shape to the later rugose corals. Because of their brief span they are an index fossil for the lower Cambrian.

Cambrian Sponge archeocyathid
Figure ??
Lower Cambrian archeocyathid

Sponges commonly have needle-like spicules which they use for movement and defense. The following figure shows a number of Cambrian sponges with spicules.


Cambrian Sponges0
Figure ??
Cambrian sponge Choiacarteri
Burgess Shale


The following Mid-Cambrian fossil sponges are listed by Charles Walcott[FOOTNOTE, Charles Doolittle Walcott, Second Contribution to the Studies on the Cambrian Faunas of North America (1886).]. Note the surface pores of the sponges indicated in the figures.

Walcott-sponge-p002-02
Figure ??a
Mid-Cambrian Sponge Leptomitus zitteli.
Georgia Formation, Parker's Quarry, Vermont
Middle Cambrian Hyalouema
showing silicious spicules. natural size.
Walcott, Cambrian Faunas, plate 2
Walcott-sponge-p004-01
Figure ??b
Mid-Cambrian Sponge
Ethmophyllum Whitneyi
Silver Peak, Nevada.
Note the pores in the magnified section.
Walcott, Cambrian Faunas, plate 4
Walcott-sponge-p005-01
Figure ??c
Mid-Cambrian Sponge
Ethmophyllum rensselaericum
Georgia Formation, Troy, NY length 0.3"
Note the pores in the magnified section.
Walcott, Cambrian Faunas, plate 5



A-4 Phylum Coelenterata (Cnidaria). All Coelenterates have stingers called cnidaria; hence this is an alternative name for the phylum.  The phylum includes hydras, medusas, jellyfish and corals. Often the life-cycle of a species may pass through several of these forms.


Middle Cambrian Microfossils
Late Cambrian Macrofossils
Cambrian Narcomedusa Cambrian medusa
Figure ??a
Medusa -- Narcomedusa
Marjum Formation (Utah)
fossils up to 8mm across.
(bar = 2mm (??))
Figure ??b
Medusas -- Scypohzoa
Krukowski Quarry, Mosinee, Wisconsin
(Individual medusas up to 2 ft. diameter)
Note water ripple marks


Cambrian Coral
Figure ??
Middle Cambrian Coral
Conasauga Shale, Cherokee County, AL

A-6 gnathostomulida. Early Cambrian "protoconodonts" are currently believed to be the unrelated remains of chaetognaths (or "arrow worms")

A-7 to A-19 are mostly soft-bodied and many are worms
.

A-12 Nematomorpha
(horsehair worms). A lower Cambrian worm of phylum Nematomorpha, in quite remarkable preservation, was discovered in 1999 in the Chengjiang Maotianshan Shales of China (Figure ??).

Lower Cambrian Maotianshania-cylindrica, Chengjiang
Figure ??
Early Cambrian Nematomorph worm
Maotianshania cylindrica







A-20 Phylum Chelicerata
. The Chelicerates include horseshoe crabs, scorpions, spiders and mites. The shells are somewhat soft and may not fossilize well. ??Cambrian examples are sometimes disputed. ???? CHECK ???? (especially if trilobites and tardigrades are removed from this phylum).

[SHOW SOME FOSSILS]

Phylum Trilobita. The Trilobite is perhaps the most remarkable Cambrian fossil. It appeared suddenly as a fully formed arthropod, and lasted for over 200 My, becoming extinct in the Permian Extinction (about 250 Ma). Trilobite fossils represent the earliest clearly defined occurrence of compound eyes. In most classification schemes the trilobite is placed in its own phylum because of its unique body structure which consists of multiple segments each with three lobes (left to right). The only comparable animal is a newly-hatched trilobite larva of the horseshoe crab (a Chelicerate), so-named because its body plan resembles a trilobite. The Cambrian trilobites are mostly small, but in later times some fossils are quite large -- up to 28 inches. See the Chapter on Phyla for further remarks on the trilobite, particularly the trilobite eyes.

trilobite Early Cambrian
Figure ??
Early Cambrian Trilobite

A-21 Phylum Mandibulata. This phylum includes the classes Hexapoda (Insecta) -- insects and spiders, Crustacea -- crabs, shrimp and lobsters, and Myriapoda -- centipedes and millipedes.

Cambrian Crustacean Phosphatocopid
Figure ??
Cambrian Crustacean Phosphatocopid
with preserved body parts
SEM photograph
<>From the Swedish Orsten fauna. Uppsala University

Orsten fauna "The initial site, discovered in 1975 by Klaus Müller and his assistants, exceptionally preserves soft-bodied organisms, and their larvae, who are preserved uncompacted in three dimensions."  For information about the Orsten fauna see also http://www.core-orsten-research.de.  CHECK THIS OUT FOR MORE PIX!!

A-22 Phylum Annelida.  segmented worms -- Earthworms, etc.

Spriggina is a possible pre-cambrian annelid. It is a segmented worm about 3 cm in length. It appears to be armored with interlocking plates. There are no Cambrian examples.

Cambrian Spriggina Annelid? (WIKI)
Figure ??
Ediacaran (pre-Cambrian) Annelid?
Spriggina




A-26 Phylum Mollusca. A Cambrian fossil Mollusc (class Monoplacophora) is named Knightoconus. This was thought to be extinct, until ten living species were discovered in 1952[FOOTNOTE: Galathea expedition: 10 living species of Neopilina galathea.]. Since that time a number of other specimens have been found. Modern species live on the ocean bed in deep water. "All extant classes of molluscs, except Scaphopoda, began at various times during the Cambrian."[FOOTNOTE: Lyell Collection, citing Runnegar & Pojeta (1974). Scaphopoda may date from the mid-Ordovician Era.]

Cambrian Mollusc Class Monoplacophora
Figure ??
Cambrian Mollusc
 Class Monoplacophora.  Knightoconus
top: fossil; bottom: living representation

Cambrian Mollusc Class Monoplacophora
Figure ??
Cambrian Gastropod Mollusc
A. attleborensis
a snail, Class Gastropoda
Aldanella ex.gr. attleborensis (Shaler & Foerste, 1888).

Cambrian Mollusc bivalve
Figure ??
Cambrian Bivalve Mollusc
 Phosphatocopina Müller, 1964 (Larva)
SEM micrograph, Oblique view.
Original size up to 5mm.
D. Walossek, Ulm[FOOTNOTE:
From the web page “Life in the Cambrian” at http://www.uni-wuerzburg.de/palaeontologie/Stuff/casu8.htm.]


A-27 Phylum TardigradaTardigrades are microscopic animals that range from 100 µm to 1,500 µm in size

Cambrian Tardigrade 530 Ma
Figure ??a
Cambrian Tardigrade (530 Ma)
Modern Tardigrade
Figure ??b
Modern Tardigrade

A-29 Phylum Bryozoa. This phylum may begin during the Ordivician Era. ???CHECK???

A-30 Phylum Brachiopoda
. The following Mid-Cambrian shellfish are listed by Charles Walcott[FOOTNOTE. Op. Cit.]. Numerous fossils of this sort have been found.



Walcott-Brachyopod-p007-01
Brachyopoda
Lingulella caelata, 2x
Middle Cambrian, Georgia Formation
ridge East of Troy, NY
Walcott, Cambrian Faunas, plate7
Walcott-Brachyopod-p008-01
Brachyopoda
Acrotreta gemma, 3x
Middle Cambrian
Pioche, Nevada
Walcott, Cambrian Faunas, plate 8
Walcott-Brachyopod-p009-04
Brachyopoda
Acrothele subsidua
Middle Cambrian
Antelope Springs, Utah
Walcott, Cambrian Faunas, plate 9







The genus Lingula (Bruguiere, 1797) is the oldest known animal genus that still containins extant species. (WIKI)
Get examples from plates in Second contribution to the studies on the Cambrian faunas of North America By Charles Doolittle Walcott (1886)

A-34 Phylum Echinodermata. The Echinoderms include starfish, sea lilies, sea urcins, and sea cucumbers.  Most of these appear later in the Ordovician Era. The sea lilies (Crinoids), or at any rate, crinoid-like fossils, occur in the Cambrian Era. Gogia is the most common example.


Cambrian Gogia Spiralis Crinoid
Figure ??
Middle Cambrian Crinoid
Gogia Spiralis  length 5.8 cm
Wheeler Shale, Utah


Cambrian Gogia Parsleyi-blastozoan Echinoderm
Figure ??
Middle Cambrian Echinoderm Blastozoan
Gogia Parsleyi
Upper Murero Formation NE Spain


A-37 Phylum Craniata.

Conodonts "teeth" are (until recently) the only fossil remains of this extinct worm-like creature. The name applies both to these bony structures and to the animal itself. They are plentiful, and amount to a trace fossil, appearing between the mid-Cambrian to the Triassic Era. In 1952 the first complete conodont fossil (from the Granton Shrimp Bed, Carboniferous Era) was described in 1963 by E.N.K. Clarkson.  Margullis calls the Conodont an early chordate class -- but not a vertebrate[
FOOTNOTE: K&D 261]. This is confirmed by some recent papers: see Conodonta: Overview at the Palaeos website. Other than these bony structures, the first full fossil was discovered by  in 1963.  Since the initial description, other complete specimens have been identified. The "switch" from phylum A-6 to A-37 was generally accepted around the turn of the (21st) Century.

Conodont
Figure ??
Conodont Apparatus
Middle Ordovician
St. Peter Formation NE Iowa.
Huaibao P. Liu, et al. The Winneshiek Lagerstätte (2007)


The following figure is a reconstruction of a conodont (from the Palaeos website):
 

conodont skeleton
Carboniferous Conodont (1983)
Figure ??
Carboniferous Conodont Fossil
   

The conodont elements can be retrieved from limestone formations by dissolving the limestone in acid. The conodont elements remain and can be used as markers to calibrate the age of other fossils by "condodont zones" which can represent time intervals to within a small fraction of a million years -- more accurate than any other means of dating[FOOTNOTE: www.ferindril.org/twiki/pub/Lab/LinkList/Barrick_Conodonts.pdf. The use of conodonts in petroleum surveys: "The petroleum industry uses conodonts as indicators of the degree of maturation of hydrocarbons in sedimentary basins as well as for biostratigraphy. Unburied and unheated conodonts have a light amber color because they retain complex organic molecules in the skeletal framework. When conodonts undergo deep burial and heating, these organic molecules change or mature in the same manner as do organic substances in the strata that are transformed into oil and natural gas. As the organics in the conodonts mature, the conodonts change color from light amber to dark amber to brown until they turn black. Experimental work and field research shows that when conodonts are light brown, the sediments have been buried and heated to a degree such that hydrocarbons have fully matured into oil". See also  W. Britt Leatham, The Hidden World of the Conodonta and  Conodonta Overview.].



Conodont "teeth": Precision fossil timepieces.
The soft-bodied conodonts lived between the Mid-Cambrian and the Permian Extinction (~520 Ma to 251 Ma). The characteristic feature of the Conodonts (and virtually the only fossil remains) were abundant microscopic "teeth"called Conodont elements, which apparently aided in breaking down food particles for digestion, and have microscopic sizes up to 0.5 mm.

These phosphatic "teeth" are liberally distributed in the fossil record over the 300 years of conodont existence, and can be used to calibrate fossil formations worldwide to within less than a million years. This is much greater accuracy than even the most precise dating with radioactive half-lives. The teeth vary their appearance slowly over time and have very distinctive shapes, so that specific micro-formations can be correlated worldwide, providing a precise way to date widely disperse formations, a fact that is widely used in the examination of drill core samples in petroleum exploration.

Conodont Elements
Figure ??
Conodont Elements






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WORKING However, a new convicing candidate for first chordate was announced in 1999 with Haikouichys -- an early (530 MYA) Cambrian fossil found in China.  These 2 to 3- cm  fossils resemble a tiny fish -- the first such animal in the fossil record (officially the first bony fish fossils are from the Ordovician Era).  Better specimens were announced in 2003 which show well-developed eyes, and other sensory structures characteristic of the cratiates, as well as the muscle blocks typical of early vertebrates  (Nature 421, pp 526-529).







The Fossil Animals of the Cambrian Era






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http://en.wikipedia.org/wiki/Geologic_timescale
"ammonites can be assigned, not just to the Mollusca, but also to the cephalopods, and indeed, are close relatives to the Coleoidea." GRAHAM E. BUDD, The Cambrian Fossil Record and the Origin of the Phyla





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NOTES
http://en.wikipedia.org/wiki/Timeline_of_plant_evolution

the role of fractals -- leaf design, tree shapes, etc. What this implies for algorithmic body plans.

http://en.wikipedia.org/wiki/Plant_evolutionary_developmental_biology


• Animals develop from a blastula.
• Plants develop from an embryo.
• Fungi develop from spores, and lack flagella and cilia
• Monerans (prokaryotes) lack a membrane bound nucleus.





Sharp Point          Origin of Body Plans: Hox genes

The puzzle of "Convergent Evolution" has been around since the beginnings of Evolutionary theory.  The puzzle is that  very similar features appear to have risen independently in widely diverse species. An example is the human eye (phylum Chordata) which is very similar to the octopus eye (phylum Mollusca). The answer, which is gradually emerging from the experimental science  evolutionary development, EvoDevo for short, is that the development of many if not all major organs and development structures (? right name?) is controlled by specific gene packages that were created in the Cambrian explosion, about 550 Ga, and which are essentially the same for huge swaths of animal types.

This observation does not, of course, explain how those packages arose in the first place.

From the viewpoint of EvoDevo, widely different morphologies occur by activating these development genes in different ways, not by creating new genes. Experiments which consist in manipulating the genetics to insert body parts in odd places has led to the identity of many of these gene packages.

Contrast with fractals (plants)







Fossil Record
 






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REFERENCES

James D. Dana Manual of Geology (1896) -- many fossils presented in systematic manner. See in particular the illustrated contents.

James W. Hagadorn Burgess Shale: Cambrian Explosion in Full Bloom (2002)
Hou Xian Guang et al. The Cambrian Fossils of Chengjiang China, Blackwell (2007).
Lynn Margulis, Kingdoms and Domains,

Patricia & Thomas Rich, Mildred & Carroll Fenton, The Fossil Book: A Record of Prehistoric Life, Dover, (1996), Chapter XXIII p. 372ff; XXXII, p. 534ff).
Colin Tudge, The Variety of Life, Oxford, 2000.

Wikipedia Articles:  Animals,

Web sites

Web Geological Time Machine (Berkeley U)

Palaeos

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First Draft Prepared September, 2010