Euryclea

“ The Carbonic species of Eurypterus develop spines wherever possible; the surface scales are produced into pointed wedges or spines; the ends of the epimera grow out to a great length; spines develop on the appendages not only in rows along the various segments but also on the lines of junction between segments: showing that the final expression of morphological characters in the eurypterids was the development of spines which was followed by extinction. ”

“ Intimately associated with the eurypterids were considerable amounts of actual plant tissue, preserved as such since Carboniferous times. It still retains its pliability, can be stripped from the shale, floated on glass slips, and made into permanent mounts. There are now about one hundred of these mounts in our collection. The preservation of actual plant tissue in such amounts and in large pieces is quite unique. The tissue is of a bright, transparent orange color. It is capable of close study, and photomicrographic reproductions of the cell structure are readily obtainable. ”

“ The mode of occurrence of the eurypterids, graptolites and plant remains is better explained on the hypothesis that the eurypterids and perhaps the plants also were fluviatile and not marine organisms. As yet the Ordovicic merostome faunas are too little known to say that the habitat can be proved to be one or the other; the most that we can say is that all the known facts are better accounted for by the fluviatile hypothesis, which is fully supported by the palaeontological and chorological data. ”

“ The tubercle, as indicated above, is one of the most constant features of the carapace in all of the species and must have a special significance. In a number of specimens examined, by the writer, under the microscope a subcircular depression is observed at or near the summit of this tubercle as in the ocelli of Eurypterus, etc. The fact that facets cannot be discerned is no criterion of their absence in the animal, for numerous trilobites and Eurypterus have as yet revealed no evidence of the compound character of their eyes, and on the other hand many species have large and distinct facets. ”

“ Let me summarize: proteasome evolution excludes the root from the proteate clade; cell envelope evolution and flagella evolution independently of each other exclude it from Posibacteria; eubacterial flagellar evolution also excludes it from Gracilicutes and Eurybacteria, and places it among the non-flagellate eubacteria that have gliding motility by slime secretion from junctional pore complexes (i.e. Glidobacteria) . Later sections will present two further transition analyses that narrow down the position of the root still further within the Glidobacteria. ”

“ Yet the facts, that no complete individual has been found, that even the fragments are of so uncertain a character that some which at first were supposed to belong to separate species have with more study been found to belong to the same species, and finally that the eurypterids, of all the myriad organisms which lived in that sea, should have been broken to fragments of which only a few are found—these facts will not admit of explanation on the ground that the eurypterids lived in the sea. ”

“ Evolutionary relationships among the four major kinds of cell. The horizontal red arrow indicates the position of the universal root as inferred from the first protein paralogue trees, i.e. between neomura and eubacteria. To determine whether the root is really there or within eubacteria, as suggested instead by many paralogue trees for metabolic enzymes, we must correctly polarize the direction of the negibacteria/posibacteria transition that took place in bacteria that had already evolved flagella. ”

“ From the Limulava to the Eurypterida is a long leap, and before it can be made without danger, many intermediate steps must be placed in position. The direct ancestor of the Eurypterida is certainly not to be seen in the highly specialized Sidneyia, and probably not in Emeraldella, but it might be sought in a related form with a few more segments. The few species now known do suggest the beginning of a grouping of appendages about the mouth, a suppression of appendages on the abdomen, and a development of gills on the thorax only. ”

“ Proteasome evolution shows that the universal root is outside a clade comprising neomura and Actinomycetales (proteates) , and thus lies within other eubacteria, contrary to a widespread assumption that it is between eubacteria and neomura. Cell wall and flagellar evolution independently locate the root outside Posibacteria (Actinobacteria and Endobacteria) , and thus among negibacteria with two membranes. Posibacteria are derived from Eurybacteria and ancestral to neomura. ”

“ The first prolific eurypterid fauna in North America, the first to offer sufficient material and a large enough representation in genera and species to make it possible to state what are the general affinities of the fauna as a whole, is the newly discovered one in the Normanskill shales at Catskill, New York, which has so far been found to contain six species, included in five genera, but undoubtedly many more will be discovered as the material is worked over. ”

“ The Bertie contains the largest eurypterid fauna of any one formation in the world, there being recorded fourteen species (39, 89) referred to four genera: Eurypterus (5 sp.) , Pterygotus (5 sp.) , Eusarcus (1 sp.) , and Dolichopterus (3 sp.) . The specimens are for the most part astonishingly well preserved, but other organisms are extremely rare. In the Museum above referred to are a few specimens of marine organisms obtained from the formation which furnished the eurypterids. ”

“ The so-called 'three domains' [ [178] are simply 'big groups' of unequal significance; two are clades (eukaryotes and archaebacteria) best treated as taxa, but not deserving equal rank [see [ [66] , for discussion of ranking] , one is a paraphyletic grade (eubacteria) that is too heterogeneous to be useful as a taxon in a formal subdivision of the kingdom Bacteria (Tables 1 and 2) .
The claim that there may be no real tree of life because of lateral gene transfer [173] is also profoundly mistaken and stems from muddling gene trees and organismal trees ”

“ Proteasome, flagella, murein wall, and outer membrane evolution now strongly corroborate this. They show that posibacteria, actinomycetes, and neomura all arose after the primary radiation of life, probably all substantially later. In my view the widespread assumption that archaebacteria are among the most ancient life forms [ [19] is profoundly mistaken [ [1] , [127] .
A root within eubacteria offers a simple perspective on the pattern of protein fold superfamilies across the three domains [117] . ”

“ There are thus ten species of eurypterids from the Devonic of Great Britain, all occurring in the Old Red Sandstone facies of deposits associated with fishes, land plants, fluviatile molluscs, myriopods and crustacea, such as the fresh or brackish-water phyllopod, Estheria, the ostracod Beyrichia and certain phyllocarids. With the exception of Pterygotus anglicus none of the eurypterids is either abundant or well preserved, most of the species being represented by a single portion of the exoskeleton or by a number of fragments. ”

“ Theory of Early Marine Habitat and Routes of Migration. As I stated above, the anomalies in the distribution of the eurypterids have not usually been given much consideration, though they are of the utmost importance. There is a current opinion that has somehow been formed about the bionomy of the eurypterid faunas and no one thinks of challenging it. When a eurypterid fauna has been found in a place where a marine fauna was not expected, it has had to be made to fit in with the preconceived opinion about the bionomic facies in which eurypterids are supposed to occur. ”

“ Many important points in the ontogeny and phylogeny of the eurypterids are here set forth for the first time, and all of the North American species are described in great detail and figured in a volume of plates that surpass all former illustrations.
I wish to express my thanks to Dr. R. Ruedemann, who allowed me to study the large collection of New York eurypterids at the State Museum in Albany; to Dr. C. D. Walcott, who showed me the large Beltina fauna and the beautiful specimens of Limulava from the Middle Cambric Stephen shale of Canada in the Smithsonian Institution at Washington, D. C ”

“ That six independent robust polarisations (plus a seventh strong but somewhat less decisive one, also discussed below: the origin of glycobacteria) are all congruent with each other and with the fossil record [ [1] shows that eobacteria are immensely older than archaebacteria. Thus there is only one primary domain of life: the paraphyletic eubacteria. Eukaryotes and archaebacteria are far younger and holophyletic sisters, secondarily derived from within one eubacterial phylum, the substantially older Posibacteria. ”

“ Only the more euryhaline marine species survive and these may in a given estuary give rise to a fauna which we may designate as a "brackish-water fauna." It will consist of forms derived in the manner just described, and these forms may become adapted to the peculiar temperature and salinity conditions prevailing in the given estuary. Thus, new mutations, varieties, and occasionally species may arise, but seldom a new genus and never a whole class of organisms. ”

“ Despite great advances in clarifying the family tree of life, it is still not agreed where its root is or what properties the most ancient cells possessed – the most difficult problems in phylogeny. Protein paralogue trees can theoretically place the root, but are contradictory because of tree-reconstruction artefacts or poor resolution; ribosome-related and DNA-handling enzymes suggested one between neomura (eukaryotes plus archaebacteria) and eubacteria, whereas metabolic enzymes often place it within eubacteria but in contradictory places. ”

“ Of the general preservation and faunal associates of these eurypterids Barrande remarks:
"Our basin, so privileged in respect to the frequency and the state of preservation of the trilobites and the other crustacea, appears, on the contrary, very poor in the fossils representing the two types of eurypterids, which are recognized in our formations. (Pterygotus and Eurypterus) .
". . . . Far from finding individuals complete and well preserved, it will prove difficult to add any new facts of importance to those already published on the organization of the species of this type. ”

“ In summing up the larval characters observed in these immature eurypterids we consider as coenogenetic or purely larval the relatively larger size of the carapace, of the compound eyes and of the swimming legs, and the smaller number of the abdominal segments; as palingenetic and phylogenetic, the approximation of the compound eyes to the margin, the prominence of the ocelli and their tumescences, the lack of differentiation of the abdomen and the smaller size of the telson. ”

“ The Eurycles is little known in private gardens, but the two species form interesting occupants of the stove or greenhouse, with their umbels of white flowers, and broad, heart-shaped or ovate leaves. E. amboinensis is a stove species about two feet high, flowering in March. The other, E. Cunninghami, likes a warm greenhouse. It grows about a foot high. One part leaf-soil to three of good loam, with a little sand, will grow them satisfactorily. After they have completed their growth water may be diminished, and finally withheld to allow them to ripen. ”

“ The entire structure of the archegonium, with its neck and canal-cells, has disappeared, and nothing is left but the indispensable oosphere. When the oosphere has been fertilised, and has commenced the cellular divisions which lead to the formation of the embryo (Fig. 255) , the synergidæ and antipodal cells are absorbed, and a cell-formation begins by a new process which emanates from the definitive nucleus and by which a parenchymatous cell-tissue, the nutritive-tissue, arises which may perhaps be considered as homologous with the endosperm of the Gymnosperms. ”

“ Rejuvenescence gives rise to a swarm-spore or zoospore. The whole of the protoplasm of a cell contracts, becomes rounded and rearranged, and escapes into the water, in which the plant floats as a mass of protoplasm, clear at one end and provided with cilia by which it is enabled to move, until after a time it comes to rest, and after secreting a wall forms a new plant by ordinary cell-division. Example: Oedogonium.
2. Free-cell formation forms swarm-spores which behave as above. ”

“ And though it is a whole month now since Eurypelma received his stab from the poisoned javelin of Pepsis, he has not recovered; nor will he ever. When you touch him, he draws up slowly one leg after another, or moves a palpus feebly. But it is living death; a hopeless paralytic is the king.
Dear reader, you are of course as bright as Mary, and so you have noticed, as she did right away, the close parallel between what happened to Eurypelma and what happened to the measuring-worms brought by Ammophila to her nest burrow as described in the first story in this book. ”

“ The extraordinary thickness of the test is shown not alone in the wholly uncompressed condition of the carapace but more in the fact that, though the abdomen has been shoved forward so that the segments are pushed into each other like joints of a telescope, they have not suffered from crumbling or folding as they always do in the other eurypterids and their greatly thickened posterior edges stand out freely. ”