Among the species of plants which characterise this formation, we may mention Neuropteris elegans, Calamites arenaceus, Voltzia heterophylla, Haidingera speciosa. The Haidingera, belonging to the tribe of Abietinæ, were plants with large leaves, analogous to those of our Damara, growing close together, and nearly imbricated, as in the Araucaria. Their fruit, which are cones with rounded scales, are imbricated, and have only a single seed, thus bearing out the strong resemblance which has been traced between these fossil plants, and the Damara.
Fig. 84.—Branch and cone of Voltzia restored.
The Voltzias ([Fig. 84]), which seem to have formed the greater part of the forests were a genus of Cupressinaceæ, now extinct, which are well characterised among the fossil Conifers of the period. The alternate spiral leaves, forming five to eight rows sessile, that is, sitting close to the branch and drooping, have much in them analogous to the Cryptomerias. Their fruit was an oblong cone with scales, loosely imbricated, cuneiform or wedge-shaped, and, commonly, composed of from three to five obtuse lobes. In [Fig. 84] we have a part of the stem, a branch with leaves and cone. In his “Botanic Geography,” M. Lecoq thus describes the vegetation of the ancient world in the first period of the Triassic age: “While the variegated sandstone and mottled clays were being slowly deposited in regular beds by the waters, magnificent Ferns still exhibited their light and elegantly-carved leaves. Divers Protopteris and majestic Neuropteris associated themselves in extensive forests, where vegetated also the Crematopteris typica of Schimper, the Anomopteris Mongeotii of Brongniart, and the pretty Trichomanites myriophyllum (Göppert). The Conifers of this epoch attain a very considerable development, and would form graceful forests of green trees. Elegant monocotyledons, representing the forms of tropical countries, seem to show themselves for the first time, the Yuccites Vogesiacus of Schimper constituted groups at once thickly serried and of great extent.
“A family, hitherto doubtful, appears under the elegant form of Nilssonia Hogardi, Schimp.; Ctenis Hogardi, Brongn. It is still seen in the Zamites Vogesiacus, Schimp.; and the group of the Cycads sharing at once in the organisation of the Conifers and the elegance of the Palms, now decorate the earth, which reveals in these new forms its vast fecundity. (See [Fig. 72], p. 168.)
“Of the herbaceous plants which formed the undergrowth of the forests, or which luxuriated in its cool marshes, the most remarkable is the Ætheophyllum speciosum, Schimp. Their organisation approximates to the Lycopodiaceæ and Thyphaceæ, the Ætheophyllum stipulare, Brongn., and the curious Schizoneura paradoxa, Schimp. Thus we can trace the commencement of the reign of the Dicotyledons with naked seeds, which afterwards become so widely disseminated, in a few Angiosperms, composed principally of two families, the Conifers and Cycadeaceæ, still represented in the existing vegetation. The former, very abundant at first, associated themselves with the cellular Cryptogams, which still abound, although they are decreasing, then with the Cycadeaceæ, which present themselves slowly, but will soon be observed to take a large part in the brilliant harmonies of the vegetable kingdom.”
The engraving at page 191 ([Plate XIII.]) gives an idealised picture of the plants and animals of the period. The reader must imagine himself transported to the shores of the Muschelkalk sea at a moment when its waves are agitated by a violent but passing storm. The reflux of the tide exposes some of the aquatic animals of the period. Some fine Encrinites are seen, with their long flexible stems, and a few Mytili and Terebratulæ. The Reptile which occupies the rocks, and prepares to throw itself on its prey, is the Nothosaurus. Not far from it are other reptiles, its congeners, but of a smaller species. Upon the dune on the shore is a fine group of the trees of the period, that is, of Haidingeras, with large trunks, with drooping branches and foliage, of which the cedars of our own age give some idea. The elegant Voltzias are seen in the second plane of this curtain of verdure. The Reptiles which lived in these primitive forests, and which would give to it so strange a character, are represented by the Labyrinthodon, which descends towards the sea on the right, leaving upon the sandy shore those curious tracks which have been so wonderfully preserved to our days.
The footprints of the reptilian animals of this period prove that they walked over moist surfaces; and, if these surfaces had been simply left by a retiring tide, they would generally have been obliterated by the returning flood, in the same manner that is seen every day on our own sandy shores. It seems more likely that the surfaces, on which fossil footprints are now found, were left bare by the summer evaporation of a lake; that these surfaces were afterwards dried by the sun, and the footprints hardened, so as to ensure their preservation, before the rising waters brought by flooded muddy rivers again submerged the low flat shores and deposited new layers of salt, just as they do at the present day round the Dead Sea and the Salt Lake of Utah.