NATURE NOTES.

New Zealand Herald, Volume LXIII, Issue 19454, 9 October 1926, Page 1 (Supplement)

NATURE NOTES.

WHEN THE EARTH WAS YOUNG BY J. DEUItMOND, F.L.S., F.Z.S. There are some grounds for a complaint by Mr. J. Martin, Ponsonby Road, that an injustice was done to the nautilus when it was stated that the tuatara is tho most aristocratic creature on earth. Some years ago Mr. Martin heard a lecture in which the lecturer referred to the nautilus and the ammonite living together in ancient times, and said that the ammonite had become extinct, but that the nautilus still was a "child'of the wandering sea," as described in Oliver Wendell Holmes' poem. The family of the nautilus, tho Nautilioidea, made its first appearance in the Upper Cambrian, far down in the Palaeozoic Era, the era of Early Life, when the world was young. The genus nautilus has continued since Silurian times, which immediately succeeded the Cambrian. The oldest types of tho nautilus are not placed in the same genus as the existing one, but shells of a nautilus very similar to shells of the living nautilus have been found in the Upper Cretaceous, the latest division of the Mesozoic Era, tho era of Middle Life, and the living genus undoubtedly is so ancient that it almost burdens the mind to think back to tho early times when it flourished. About 2500 species of the Nautilioidea are represented by fossils. The beauty of some of the /ossil forms was matched by their size; tney were more than 6ft. long. Only a few species of the genus nautilus have survived. The chambered nautilus, or pearly nautilus, whose chambered shell, with its pearly interior, suggested the tender poem of the " Autocrat of the Breakfast Table," is one of them. The chambered nautilus is not found in New Zealand waters, but the paper nautilus is. It is the naturalists' Argonauta argo. Another New Zealand species very much like the paper nautilus is Argonauta tuberculata. The paper nautilus has been described as the most interesting of all the octopods, on account of the mystery, myth and uncertainty that once were associated with it. There was a belief in former times that it did not make its shell, but usurpinglv took possession of another creature's shell and used it as a place of abode or as a boat, raising extended arms like sails to catch the breeze. The female panenautilus builds her own lovely mansion, retains it in position with a pair of arms adapted for that purpose, and places her eggs in it; and there, probably, her young arc rocked in a cradle of the deep. Ammonites began to appear for the first time in the Permian Period, which closed the Palaeozoic Era. Later, in tho Jurassic Period, a division of the Mesozoic Era, they were so plentiful and so important that Jurassic times have been called the Age of Ammonites. Many species of ammonites —more than 5000 have been described—were distributed in almost all parts of the world. The cause of their extinction about the end of the Mesozoic Era is a pnzzle. Sir Archibald Geikie regarded their absence from Tertiary rocks as one of the most strikfeatures in the whole series of formation that constitute the great geological record. He points out that it is amazing that thousands of species which flourished in the Mesozoic, giving a distinctive character to marine life, should, apparently, not have survived later than those times. He regarded the ammonites as a race that outlived its vigour and decayed from old ago, or fell before an uncongenial environment in the Cretaceous seas in which they found themselves. Like the nautilus, they were members of the highest division of the cephalopods, to which all cuttle fish belong. The ammonites' shells resembled the shells of the nautilus, but were more highly ornamented. Their name is derived from the resemblance of their shells to the rams' horns on the head of Jupiter Ammon. An interesting collection of ammonites that lived in Upper Cretaceous times vvas made at Batley, and on the Arapaoa arm of the Kaipara Harbour. The distribution of species of fossil ammonites in New Zealand favours the theory of a close relationship between New Zealand and South India in the Upper Cretaceous. Tho Jurassic and Cretaceous divisions of the Mesozoic Era are characterised by an extraordinary exuberance of ammonites and of saurians. Some of the richest fossiliferous fields in New Zealand are in Cretaceous rocks at Amuri Bluff, North Canterbury, where many remains of reptiles have been found. These rocks are part of a belt of Cretaceous rocks, not quite continuous, which runs from Cape Campbell, in Marlborough, to tho Waipara district, North Canterbury. An extensive belt near the east coast of the Wellington Province, and in Southern Hawke's Bay, has been assigned tto tho Cretaceous. The Tertiary Era followed close on tho heels of the Mesozoic Era, but Tertiary life is marked by the absence of many creatures that had thoroughly established themselves in tho Mesozoic, and by the sudden appearance of many highly-organised forms of life. Of these there has been found no trace of probable ancestors. The pterodactyls, in spite of having been endowed with the power of flight, the plesiosaurs, the ichthyosaurs and many species of dinosaurs, near the end of the Mesozoic Era, disappeared "as completely as if they had never existed." Jurassic rocks in Wyoming, Utah, Dakota and Colorado hold remarkable collections of extinct dinosaurs, tortoises, pterodactyls, crocodiles and lizards. Among these are forma related to tho tuatara. It is the only living representative of the palaeosatirs —"ancient reptiles"—whose golden age was in the Mesozoic Era, before man became a living soul. Dinosaurs' eggs on which American men of science recently feasted their eyes were laid beneath the Flaming Cliffs, in the Gobi Desert, Central Asia, in the Upper Cretaceous Period. This, as stated previously, brought tho Mesozoic Era to an end. Ten million years ago, if geological computations are correct, a goblin-like reptile stood on the edge of a shallow Cretaceous basin, made a nest and laid its eggs. "Its great round eyes stared unblinkinglv from a thin, hatchet face, ending in a hooked beak," Dr. Roy C. Andrews, discoverer of the eggs, states. "Its head sloped up and back with a circular bony frill, which formed a solid armature over the neck and foreshoulders. Low in front and high behind, with its nine-foot body ending in a thick tail, it seemed a horrid nightmare fantasy. Slowly it waddled down the slope and settled itself into tho red sand, and there in the hollow it left 20. elliptical white eggs, fated, though warmed by the sun's rays, never to be hatched." Them were big dinosaurs and little dinosaurs. The eggs found at tho Flaming Cliffs were about 9in. long. They were laid by dinosaurs about Oft. long, mostly tail. Some of the eggs had been crushed, but the pebbled surface of the shells is as perfect as if tho eggs had been laid yesterday, instead of 10,000,000 years ago. Tho* shells are about onesixteenth of an inch thick. In one clutch, tho eggs were smaller than other eggs. It is presumed that the small ones were laid by a member of a small species of dinosaur. In two eggs that had been broken in half there can be traced the delicate bones of embryonic dinosaurs. In that dinosaurion incubator there were the remains of baby dinosaurs. These, probably, had been hatched only a few weeks. Other remains represent an amazing sories of dinosaurian growth, from young to adults Oft. long.