Quotes

"கலைக்களஞ்சியம் என்பது அகரவரிசையில் தூசிசேகரிக்கும் ஒரு அமைப்பு. "

Podokesaurus

 Podokesaurus is a genus of coelophysoid dinosaur that lived in what is now the eastern United States during the Early Jurassic Period. The first fossil was discovered by the geologist Mignon Talbot near Mount Holyoke, Massachusetts, in 1910. The specimen was fragmentary, preserving much of the body, limbs, and tail. In 1911, Talbot described and named the new genus and species Podokesaurus holyokensis based on it. The full name can be translated as "swift-footed lizard of Holyoke". This discovery made Talbot the first woman to find and describe a non-avian dinosaur. The holotype fossil was recognised as significant and was studied by other researchers, but was lost when the building it was kept in burned down in 1917; no unequivocal Podokesaurus specimens have since been discovered. It was nominated as state dinosaur of Massachusetts in 2021.

Estimated to have been about 1 m (3 ft) in length and 1–40 kg (2–90 lb) in weight, Podokesaurus was lightly constructed with hollow bones, and would have been similar to Coelophysis, being slender, long-necked, and with sharp, recurved teeth. The vertebrae were very light and hollow, and some were slightly concave at each end. The cervical (neck) vertebrae were relatively large in length and diameter compared to the dorsal (back) vertebrae, and the caudal (tail) vertebrae were long and slender. The humerus (upper-arm bone) was small and delicate, less than half the length of the femur (thigh-bone). The pubis (pubic bone) was very long, expanding both at the front and hind ends. The femur was slender, nearly straight, had thin walls, and was expanded at the back side of its lower end. The three metatarsals of the lower leg were closely appressed together forming a compact structure.


Since it was one of few small theropods known at the time it was described, the affinities of Podokesaurus were long unclear. It was placed in the family Podokesauridae along with other small theropods, and was speculated to have been similar to a proto-bird. It was suggested it was a synonym of Coelophysis and a natural cast specimen was assigned to it, but these ideas are not currently accepted. The family Podokesauridae is not in use anymore, having been replaced by Coelophysidae, and Podokesaurus is thought to have been a coelophysoid. As such, Podokesaurus would have been a fleet-footed predator, with powerful forelimbs and grasping hands. It is estimated it could have run at 15–20 km/h (9–12 mph). Podokesaurus is thought to have been collected from the Portland Formation, the age of which has long been unclear, but is currently believed to date to the Hettangian–Sinemurian stages of the Early Jurassic, between 201 and 190 million years ago.a

History of India

 According to consensus in modern genetics anatomically modern humans first arrived on the Indian subcontinent from Africa between 73,000 and 55,000 years ago. However, the earliest known human remains in South Asia date to 30,000 years ago. Settled life, which involves the transition from foraging to farming and pastoralism, began in South Asia around 7,000 BCE. At the site of Mehrgarh, Balochistan, Pakistan, presence can be documented of the domestication of wheat and barley, rapidly followed by that of goats, sheep, and cattle. By 4,500 BCE, settled life had spread more widely, and began to gradually evolve into the Indus Valley Civilization, an early civilization of the Old world, which was contemporaneous with Ancient Egypt and Mesopotamia. This civilisation flourished between 2,500 BCE and 1900 BCE in what today is Pakistan and north-western India, and was noted for its urban planning, baked brick houses, elaborate drainage, and water supply.

In early second millennium BCE persistent drought caused the population of the Indus Valley to scatter from large urban centres to villages. Around the same time, Indo-Aryan tribes moved into the Punjab from Central Asia in several waves of migration. Their Vedic period (1500-500 BCE) was marked by the composition of the Vedas, large collections of hymns of these tribes. Their varna system, which evovled into the caste system, consisted of a hierarchy of priests, warriors, and free peasants, excluded indigenous peoples by labeling their occupations impure. The pastoral and nomadic Indo-Aryans spread from the Punjab into the Gangetic plain, large swaths of which they deforested for agriculture usage. The composition of Vedic texts ended around 600 BCE, when a new, interregional culture arose. Small chieftaincies, or janapadas, were consolidated into larger states, or mahajanapadas, and a second urbanisation took place. This urbanisation was accompanied by the rise of new ascetic movements in Greater Magadha, including Jainism and Buddhism, which opposed the growing influence of Brahmanism and the primacy of rituals, presided by Brahmin priests, that had come to be associated with Vedic religion, and gave rise to new religious concepts.In response to the succes of these movements, Vedic Brahmanism was synthesised with the preexisting religious cultures of the subcontinent, giving rise to Hinduism.

Most of the Indian subcontinent was conquered by the Maurya Empire during the 4th and 3rd centuries BCE. From the 3rd century BCE onwards Prakrit and Pali literature in the north and the Tamil Sangam literature in southern India started to flourish. Wootz steel originated in south India in the 3rd century BCE and was exported to foreign countries. During the Classical period, various parts of India were ruled by numerous dynasties for the next 1,500 years, among which the Gupta Empire stands out. This period, witnessing a Hindu religious and intellectual resurgence, is known as the classical or "Golden Age of India". During this period, aspects of Indian civilisation, administration, culture, and religion (Hinduism and Buddhism) spread to much of Asia, while kingdoms in southern India had maritime business links with the Middle East and the Mediterranean. Indian cultural influence spread over many parts of Southeast Asia, which led to the establishment of Indianised kingdoms in Southeast Asia (Greater India).


The most significant event between the 7th and 11th century was the Tripartite struggle centred on Kannauj that lasted for more than two centuries between the Pala Empire, Rashtrakuta Empire, and Gurjara-Pratihara Empire. Southern India saw the rise of multiple imperial powers from the middle of the fifth century, most notably the Chalukya, Chola, Pallava, Chera, Pandyan, and Western Chalukya Empires. The Chola dynasty conquered southern India and successfully invaded parts of Southeast Asia, Sri Lanka, the Maldives, and Bengal in the 11th century. In the early medieval period Indian mathematics, including Hindu numerals, influenced the development of mathematics and astronomy in the Arab world.


Islamic conquests made limited inroads into modern Afghanistan and Sindh as early as the 8th century, followed by the invasions of Mahmud Ghazni. The Delhi Sultanate was founded in 1206 CE by Central Asian Turks who ruled a major part of the northern Indian subcontinent in the early 14th century, but declined in the late 14th century, and saw the advent of the Deccan Sultanates. The wealthy Bengal Sultanate also emerged as a major power, lasting over three centuries. This period also saw the emergence of several powerful Hindu states, notably Vijayanagara and Rajput states, such as Mewar. The 15th century saw the advent of Sikhism. The early modern period began in the 16th century, when the Mughal Empire conquered most of the Indian subcontinent, signalling the proto-industrialization, becoming the biggest global economy and manufacturing power, with a nominal GDP that valued a quarter of world GDP, superior than the combination of Europe's GDP. The Mughals suffered a gradual decline in the early 18th century, which provided opportunities for the Marathas, Sikhs, Mysoreans, Nizams, and Nawabs of Bengal to exercise control over large regions of the Indian subcontinent.


From the mid-18th century to the mid-19th century, large regions of India were gradually annexed by the East India Company, a chartered company acting as a sovereign power on behalf of the British government. Dissatisfaction with company rule in India led to the Indian Rebellion of 1857, which rocked parts of north and central India, and led to the dissolution of the company. India was afterwards ruled directly by the British Crown, in the British Raj. After World War I, a nationwide struggle for independence was launched by the Indian National Congress, led by Mahatma Gandhi, and noted for nonviolence. Later, the All-India Muslim League would advocate for a separate Muslim-majority nation state. The British Indian Empire was partitioned in August 1947 into the Dominion of India and Dominion of Pakistan, each gaining its independence.

COVID-19 vaccination for 18-45 age group is....

COVID-19 vaccination for 18-45 age group is now open


 In the third phase of the COVID-19 vaccination drive, all those above the age of 18 years are now eligible for a vaccine from May 1, according to the central government. Many states reporting a shortage of vaccines have said the program will start once there is enough stock.