The Carboniferous 354 to 290 Million Years Ago

The Carboniferous Period occurred from about 354 to 290 million years ago during the late Paleozoic Era. The term "Carboniferous" comes from England, in reference to the rich deposits of coal that occur there. These deposits of coal occur throughout northern Europe, Asia, and midwestern and eastern North America. The term "Carboniferous" is used throughout the world to describe this period, although this period has been separated into the Mississippian (Lower Carboniferous) and the Pennsylvanian (Upper Carboniferous) in the United States. This system was adopted to distinguish the coal-bearing layers of the Pennsylvanian from the mostly limestone Mississippian, and is a result of differing stratigraphy on the different continents. Coal swamp Carboniferous Forest : The Carboniferous Period is famous for its vast coal swamps, such as the one depicted here. Such swamps produced the coal from which the term "Carboniferous", or "carbon-bearing" comes. In addition to having the ideal conditions for the beginnings ofcoal, several major biological, geological, and climatic events occurred during this time. One of the greatest evolutionary innovations of the Carboniferous was the amniote egg, which allowed for the further exploitation of the land by certain tetrapods. The amniote egg allowed the ancestors of birds, mammals, and reptiles to reproduce on land by preventing the desiccation of the embryo inside. There was also a trend towards mild temperatures during theCarboniferous, as evidenced by the decrease in lycopods and large insects and an increase in the number of tree ferns. Geologically, the Late Carboniferous collision of Laurussia (present-day Europe and North America) into Godwanaland (present-day Africa and South America) produced the Appalachian mountain belt of eastern North America and the Hercynian Mountains in the United Kingdom. A further collision of Siberia and eastern Europe created the Ural Mountains. The stratigraphy of the Lower Carboniferous can be easilydistinguished from that of the Upper Carboniferous. The environment of the Lower Carboniferous in North America was heavily marine, when seas covered parts of the continents. As a result, most of the mineral found in Lower Carboniferous is limestone, which are composed of the remains of crinoids, lime-encrusted green algae, or calcium carbonate shaped by waves. The North American Upper Carboniferous environment was alternately terrestrialand marine, with the transgression and regression of the seas caused by glaciation. These environmental conditions, with the vast amount of plant material provided by the extensive coal forests, allowed for the production of coal. Plant material did not decay when the seas covered them and pressure and heat eventually built up over the millions of years to transform the plant material to coal.

Zaman manusia purba

manusia purba Pithecanthropus erectus

manusia purba Pithecanthropus erectus
Manusia Jawa adalah salah satu jenis Homo erectus yang pertama kali ditemukan. Awalnya, manusia ini diberi nama ilmiah Pithecanthropus erectus oleh Eugène Dubois, orang yang berhasil menemukan fosilnya di Trinil pada tahun 1891. Nama Pithecanthropus erectus sendiri berasal dari akar bahasa Yunani dan latin dan memiliki arti manusia-kera yang dapat berd
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Ketika itu, Eugène Dubois tidak berhasil mengumpulkan fosil Pithecanthropus secara utuh melainkan hanya tempurung tengkorak, tulang paha atas dan tiga giginya saja. Dan sampai saat ini, belum ditemukan bukti yang jelas bahwa ketiga tulang tersebut berasal dari spesies yang sama.[1] Sebuah laporan berisi 342 halaman ditulis pada waktu itu tentang keraguan validitas penemuan tersebut. Meskipun demikian manusia Jawa masih dapat ditemukan di buku-buku pelajaran saat ini. Fosil yang lebih lengkap kemudian ditemukan di desa Sangiran, Jawa Tengah, sekitar 18km ke Utara dari kota Solo. Fosil berupa tempurung tengkorak manusia ini ditemukan oleh Gustav Heinrich Ralph von Koenigswald, seorang ahli paleoantropologi dari Berlin, pada tahun 1936. Selain fosil, banyak pula penemuan-penemuan lain di situs sangiran ini[2].
Sampai temuan manusia yang lebih tua lainnya ditemukan di Great Rift Valley, Kenya, temuan Dubois dan von Koenigswald merupakan manusia tertua yang diketahui. Temuan ini juga dijadikan rujukan untuk mendukung teori evolusi Charles Darwin dan Alfred Russel Wallace. Banyak ilmuwan pada saat itu yang juga mengajukan teori bahwa Manusia Jawa mungkin merupakan mata rantai yang hilang antara manusia kera dengan manusia modern saat ini. Saat ini, antropolog bersepakat bahwa leluhur manusia saat ini adalah Homo erectus yang hidup di Afrika (dikenal pula dengan nama Homo ergaster).