The Brazilian samba, like a number of Latin American dances, combines African and European artistic influences. These dancers are performing the samba at a nightclub in Rio de Janeiro.
© Günter Gräfenhain, SIME/4Corners Images

It’s time to put on your dancing shoes because National Ballroom Dancing Week is here. From September 16th to the 25th, try out the following fun dance styles in your living room. There are 12 types of ballroom dance: 1) bolero, 2) cha-cha, 3) East Coast swing, 4) fox trot, 5) jive, 6) mambo, 7) paso double, 8) rumba, 9) samba, 10) tango, 11) Viennese waltz, and 12) waltz. Let’s look at a few of these.

Samba is a popular Afro-Brazilian style of music and dance. The term Afro-Brazilian is used to refer to Brazilians of largely African descent. Samba is best known for the central role it plays in the famous Carnival festival in Brazil. Samba music consists of layers of syncopated (irregularly accented) rhythms played in 2/4 or 4/4 time. Samba can be danced solo, in pairs, or in groups. It involves quick forward and backward steps. Dancers sway their hips while stepping and use various sweeping or energetic arm movements.

In Brazil, samba styles vary by region. For example, the samba de roda is a style performed in Brazil’s northern states. This style of samba usually involves women dancing in a circle. Samba-lenço is popular in Brazil’s central and southern states. Samba-lenço dancers hold a handkerchief while performing. Samba carnavalesca is the most internationally recognized style of samba. Dancers perform the samba carnavalesca each year during the Carnival festival.

Samba has its roots in the music and dance of the African nation of Angola. Scholars think the word samba comes from the Kimbundu word semba, which describes a belly-bumping dance move used in some styles of samba. Enslaved African people brought the music and dance style to Brazil. Around 1900, samba became associated with the Carnival celebration in Rio de Janeiro. Soon it became a symbol of national identity in Brazil.

Ballroom dancing is a form of dancing for couples. Various ballroom dances originated in Europe, the United States, and Latin America. These dances then spread throughout the rest of the world as both a popular social activity and a competitive sport.
© Jeffrey Dunn, The Viesti Collection

Rumba, also spelled rhumba, is a Latin ballroom dance that originated in Africa and achieved its modern form in Cuba. Couples perform the rumba in 4/4 time with a quick-quick-slow rhythm. The rumba emphasizes a swaying hip motion that is achieved by taking small steps with the knees relaxed. Steps are typically performed in a square pattern. The rumba is most often accompanied by music with a repeated beat played on percussion instruments.

A version of the rumba was first introduced into the United States from Cuba about 1914. However, the dance’s exaggerated hip movements were considered too sexually suggestive and the dance did not gain acceptance. A more refined version was introduced about 1930. The dance maintained its popularity in the 1930′s and 1940′s, especially in England, where ballroom dance teachers standardized the figures and step rhythms. Rumbas also appear in music not intended for ballroom dancing, as in Darius Milhaud‘s ballet La creation du monde (1923).

Tango is the national dance and music of Argentina. These couples are dancing at a milonga in Plaza Dorrego, in the San Telmo neighborhood of Buenos Aires. Milongas are social events for dancing tango. They have their own special etiquette. For example, couples circulate around the dance floor in a counterclockwise direction.
© Jeff Greenberg, UIG/Getty Images

Tango was the first Latin American dance to gain great international popularity. The tango is a ballroom dance for a couple in slow 2/4 or 4/4 time. The dancers alternate long, slow steps with short, quick steps, sometimes making sudden turns and striking dramatic poses.

The tango was danced in the United States about 1912 by Vernon and Irene Castle, a famous ballroom dancing team. It also became popular in Paris and London. Today’s tango is related to an Argentine dance called the milonga, a Cuban dance called the habanera, and a tango from Spain‘s Andalusian region.

The waltz became the most fashionable social dance of the late 1800′s. It originated in Germany and Austria and soon spread to other countries. The waltz inspired some of the finest dance music of the period and also added beauty and elegence to many romantic ballets of the 1800′s.
Emperor Franz Joseph at a Ball in Vienna(about 1900), a gouache painting on canvas by Wilhelm Gause; Museum der Stadt, Vienna/ET Archive, London from Superstock

Waltz is a ballroom dance in 3/4 time characterized by its swift gliding turns. The dance was enormously popular throughout the 1800′s. The term waltz is also used for the music that accompanies this dance. The waltz has been danced in two distinct styles, the three-step and the two-step. In Europe, especially in Vienna, the dancers waltzed much faster than they waltzed in North America.

The waltz developed rapidly in the last years of the 1700′s. It emerged from a group of south German and Austrian dances involving the turning motion of the dancers in a close embrace position. The popularity of waltzes among young people led some authorities to outlaw the dance because it was thought to be immoral for couples to dance so closely.

February 28, 2020

On March 1, 1870, 150 years ago this Sunday, Paraguay’s President Francisco Solano López was killed by Brazilian troops in the Cerro Corá valley of northeastern Paraguay. López’s death marked the end of the War of the Triple Alliance (also called the Paraguayan War), the bloodiest war in Latin American history. The conflict had begun in 1864 and pitted Paraguay against the nearby nations of Argentina, Brazil, and Uruguay—the “Triple Alliance.” Paraguay lost the war, its population was decimated, and much of the country was destroyed.

This is the last known photograph of Paraguayan President Francisco Solano López. He was killed 150 years ago this Sunday on March 1, 1870. credit: Public Domain

It is a grim anniversary, but the War of the Triple Alliance still calls forth nationalistic pride in many Paraguayans. The country is marking the sesquicentennial of the end of the war with concerts, book launches, and conferences in Asunción, the capital, as well as special commemorations in the capital and at López’s death site along the Aquidabán Niguí River.

In 1862, as the United States struggled through a bloody Civil War, Paraguay’s first president, Carlos Antonio López, died after 21 years in power. His son, Francisco Solano López, then took over as a president with dictatorial powers. Francisco believed that Argentina and Brazil wished to occupy Paraguay and Uruguay, so he signed a defense treaty with Uruguay. In 1864, Paraguay went to war against Brazil to defend Uruguay’s government. After Argentina refused to let Paraguayan troops cross its territory to attack Brazil, López declared war on Argentina as well. In 1865, Brazil helped a new government take hold in Uruguay, which joined with Argentina and Brazil to form the Triple Alliance against Paraguay.

Paraguay fought the nearby countries of Argentina, Brazil, and Uruguay (to the southeast, not on the map) in the War of the Triple Alliance (1864-1870). credit: World Book map; map data (c) MapQuest.com, Inc.

After initial Paraguayan victories, the turning point of the war came at the 1866 Battle of Tuyutí in southwestern Paraguay. In the bloodiest battle ever in South America, some 17,000 soldiers were killed at Tuyutí—most of them Paraguayan. A series of desperate battles followed as the Alliance armies gained the upper hand. By January 1869, Alliance troops had captured Asunción and controlled much of Paraguay, but López and a stalwart group of soldiers continued fighting a guerrilla campaign in the mountains. (Guerrilla warfare is conducted by roving bands of fighters who stage ambushes, sudden raids, and other small-scale attacks.) Brazilian troops eventually caught up with López and his remaining forces in the Cerro Corá valley, where the war ended with López’s death on the battlefield in 1870.

The war left Paraguay in ruins. Some historians estimate that the country lost about 60 percent of its prewar population, including nearly 90 percent of its men. In total, an estimated 400,000 people died in the conflict. Paraguay also lost a fourth of its territory. After the war, power struggles among rival political groups plagued the country. More than 30 presidents headed Paraguay’s government from 1870 to 1932.

December 11, 2019

Today, December 11, people celebrate National Tango Day (El Día del Tango) in Argentina, where the tango dance originated and is arguably the national pastime. (Others might say it is fútbol, or soccer.) Tango, which also has roots in neighboring Uruguay, was the first Latin American dance to gain great international popularity. The date for National Tango Day, December 11, marks the birthdays of the Argentine tango music legends Carlos Gardel (in 1890) and Julio de Caro (in 1899)

Tango is the national dance and music of Argentina. The couples shown here are dancing in a street in Buenos Aires. Credit: © Robert Frerck, Stone/Getty Images

National Tango Day includes dance spectaculars throughout Argentina and special performances by the 24-couple National Tango Team. Tango competitions and celebrations take over Buenos Aires, the Argentine capital and center of tango culture. The complexity and popularity of tango music and dance have influenced many other arts as well as every day life, emotion, and philosophy in Argentina.

The singer Carlos Gardel grew up in Buenos Aires and became one of the biggest tango stars in the world. Credit: Public Domain

The tango is a ballroom dance for a couple in slow 2/4 or 4/4 time. The dancers alternate long, slow steps with short, quick steps, sometimes making sudden turns and striking dramatic poses. The tango was first danced in the late 1800′s by people of the Río de la Plata region along the border of Argentina and Uruguay. The tango found firm footing in Buenos Aires before spreading to other parts of Latin America.

Tango was introduced in the United States about 1912 by Vernon and Irene Castle, a famous ballroom dancing team. The dance became popular and soon spread to Paris, London, and other parts of the world.  Today’s tango is related to an Argentine dance called the milonga, a Cuban dance called the habanera, and a tango from Spain’s Andalusian region.

January 24, 2018

On Saturday, January 20, weary and filthy racers from all over the world pulled their off-road vehicles onto the streets of Córdoba, a city in central Argentina, completing the final stage of the Dakar Rally. The racers entered the city and crossed the finish line after 14 grueling days of gritty cross-country racing, covering 5,457 miles (8,782 kilometers) of dirt, rock, and sand. The race began in Lima, Peru, on January 6, running east into Bolivia before winding south to Argentina.

A lone biker follows the track through a remote part of northern Argentina during the Dakar Rally. Credit: © Dan Istitene, Getty Images

The Dakar Rally, once known as the Paris-Dakar Rally, is an annual cross-country endurance race. The rally includes five different vehicle categories: cars; motorcycles; quads (all-terrain vehicles, or ATV’s); trucks; and utility task vehicles, or UTV’s (a two-seater style of ATV also known as a Side-by-Side, or SxS). The first Dakar Rally began on Dec. 26, 1978, as 182 motorcycles and cars revved their engines on the Place du Trocadéro in Paris, France, preparing for the 6,200-mile (10,000-kilometre) journey to Dakar, the capital of Senegal. Covering more than 500 miles (800 kilometers) per day, the winning racers crossed the Dakar finish line on Jan. 14, 1979 (just 74 vehicles completed the race). The racers followed a route from Paris to Marseille, where boats carried them across the Mediterranean Sea to Algeria. From there, the route continued through the dunes and dust of Niger, Mali, Upper Volta (now Burkina Faso), and, finally, Senegal.

The Dakar Rally continued annually and gained popularity, reaching a peak of 688 racers in 2005. In 2008, security threats in Mauritania (Mali’s neighbor to the west) shut down the race, and it was moved to the deserts and scrubland of South America. The 2018 Dakar Rally began with 525 racers from 54 countries. The winning drivers in each category came from Austria, Brazil, Chile, Russia, and Spain. Accidents, mechanical failures, and other problems accounted for a high attrition rate (percentage of racers unable to finish the rally) of 45 percent in 2018.

To compensate for negative impacts of the race on the environment, Dakar Rally sponsors donate large sums to the Madre de Dios project that works to protect the Amazon rain forest and other natural habitats of South America. Race routes avoid sensitive archaeological or paleontological sites, and strict cleanup and recycling rules ensure the integrity of the stunning natural landscapes that define the spectacle of the rally.

March 24, 2017

If you are lucky enough to go camping along the banks of the Paraná River in the Argentine Pampas of South America, be sure to carry an ultraviolet (UV) flashlight with you. Among the leaves, vines, and creepy crawlies, you just might find glow-in-the-dark frogs! A couple of weeks ago, a team of researchers from the University of Buenos Aires and Brazil’s University of São Paulo discovered the first fluorescent frog near Santa Fe, a city in northeastern Argentina. Yes, these frogs can create their own light! This first fluorescent frog, the polka dot tree frog, is already well-known and commonly found throughout the Pampas and the nearby Amazon Basin, so it is not a new species. But scientists did not know the amphibians had fluorescent “power” until now.

The one-and-only glow-in-the-dark polka dot tree frog changes color at sunset. Credit: © Carlos Taboada, Bernardino Rivadavia Natural Sciences Museum (Buenos Aires)

The capability to absorb light at short wavelengths and re-emit it at longer wavelengths is called fluorescence. It is uncertain why some animals have this ability, but it may be used to communicate, for camouflage, or to attract a mate. Fluorescence is fairly common in the ocean, where fish, plankton, and even sea turtles can emit their own light. In the desert, scorpions also glow in the dark. But never before has anyone seen a phosphorescent amphibian. Scientists found that the 1.2-inch (3-centimeter) polka dot tree frog’s glowing ability come from a compound found in the lymph and skin glands of its translucent (see-through) body. The fluorescence does not work in complete darkness, but rather at twilight, when the frog’s skin has recently absorbed light, and its color goes from a dull pale green with speckled white, yellow, or reddish spots, to a bright green with dark spots.

A polka dot tree frog (Hypsiboas punctatus) pretends to be just like any other tree frog during the day. Credit: © Patrick K. Campbell, Shutterstock

There are thousands of frog species around the world, and they live on every continent except Antarctica. If you pay attention, you’ll notice that new frog species are discovered fairly often. Their sometimes tiny size and reclusive habits in the remotest of forests make some frogs extremely hard to find. The polka dot tree frog may be the first fluorescent frog known to science, but the ever-evolving natural world is bound to be hiding others in the darkest corners of Earth—just keep your UV light on and your eyes open!

February 10, 2017

On Sunday, February 12, celebrations in Chile will mark the 200^th anniversary of the Battle of Chacabuco, a key event in the history of the South American country. The battle took place on Feb. 12, 1817, near Santiago, the capital, during Chile’s struggle for independence from Spain. The Army of the Andes (made up of Chilean and Argentine rebels) defeated a Spanish-led army at Chacabuco—a rebel victory that led to Chilean independence in 1818. The battle is famous for the actions of Argentine General José de San Martín and Chilean patriot Bernardo O’Higgins, who became Chile’s first head of state.

Chilean and Argentine soldiers attend a ceremony at the Monument to the Victory of Chacabuco on Feb. 12, 2007. The monument, built in 1971, stands on the site of the former battlefield. Credit: Kiko Benítez S. (licensed under CC BY-SA 3.0)

In the mid-1500’s, Spain established a colony that became known as the Viceroyalty of Peru. By the late 1700′s, the colony included modern-day Chile, Peru, and western Bolivia. Santiago was the colony’s administrative center in Chile. In 1808, France forced Spain’s king from the throne during the Napoleonic Wars (1796-1815). With Spanish attention turned toward Europe, revolts erupted in many of Spain’s colonies, including the Viceroyalty of Peru. In 1814, Spain and its officials in America increased their efforts to reestablish authority, beginning a bloody period known as la Reconquista (the Reconquest) of Spanish America. At first, Spanish-led royalist armies put down several colonial revolts. However, rebel armies eventually got the upper hand, leading to independence for several Latin American countries.

The 1817 Battle of Chacabuco was fought in this scenic valley near Santiago, Chile. The valley is now home to far more guanacos than soldiers. Carretera Austral. Credit: © Shutterstock

In 1810, revolutionary factions calling for self-rule gained political control of Chile. Disagreements between O’Higgins and other Chilean leaders weakened the new government, however, and the Spanish royalist faction (with support from Peru) regained control of Chile in 1814. O’Higgins fled with a rebel army to neighboring Argentina, where he joined forces with San Martín. San Martín helped secure Argentine independence in 1816. He then led O’Higgins and their combined Army of the Andes into Chile in January 1817, a journey that included a dangerous and costly crossing of the Andes Mountains. More than 1,000 soldiers died from cold, disease, and hunger during the 300-mile (480-kilometer) crossing, but roughly 3,600 surviving rebels neared Santiago in early February.

Argentine General and South American liberator José de San Martín. Credit: © Thinkstock

The Spanish royalist army had expected the rebels to take a different route through the Andes, and most of its forces were far from Santiago. Some 1,500 troops still in the area began fortifying positions north of Santiago at Chacabuco, a ridge at the head of a wide valley. Before they could secure the high ground, however, San Martín and the Army of the Andes attacked the royalists on the morning of February 12. O’Higgins led a furious assault on the main royalist forces as a second rebel force under Argentine General Miguel Soler moved to attack from the side and the rear. Fierce fighting took place until an afternoon attack led by San Martín reinforced O’Higgins and overran the battered royalist forces as Soler blocked their retreat.

Chilean patriot and leader Bernardo O’Higgins. Credit: © Kean Collection/Getty Images

About 500 royalist troops were killed at Chacabuco, and more than 600 were captured. The Army of the Andes lost some 130 killed and wounded. The remaining Spanish and royalist troops withdrew to strongholds in southern Chile or escaped to Peru. O’Higgins took control of Chile, which declared its independence in February 1818. The royalists tried once more to retake Chile, but they were eventually defeated at the Maipo River (also spelled Maipú) near Santiago on April 5, 1818—the final major battle in Chile’s war of independence. The Army of the Andes then joined with rebels in Peru, helping win independence for that nation in 1826.

January 17, 2017

On Saturday, January 14, weary and filthy racers from all over the world pulled their off-road vehicles onto the streets of Buenos Aires, the capital of Argentina, completing the final stage of the Dakar Rally. The racers entered the city and crossed the finish line after 12 grueling days of gritty cross-country racing, covering 5,457 miles (8,782 kilometers) of dirt, rock, and sand. The race began in Asunción, Paraguay, on January 2, running north into Bolivia before winding back south to Argentina.

An off-road racer climbs the desert dunes near Ica, Peru, during the 2013 Dakar Rally. Credit: © Christian Vinces, Shutterstock

The Dakar Rally, once known as the Paris-Dakar Rally, is an annual cross-country endurance race. The rally includes five different vehicle categories: cars, motorcycles, quads (all-terrain vehicles, or ATV’s), trucks, and—new this year—utility task vehicles, or UTV’s (a two-seater style of ATV). The first Dakar Rally began on Dec. 26, 1978, as 182 motorcycles and cars revved their engines on the Place du Trocadéro in Paris, France, preparing for the 6,200-mile (10,000-kilometre) journey to Dakar, the capital of Senegal. Covering more than 500 miles (800 kilometers) per day, the winning racers crossed the Dakar finish line on Jan. 14, 1979 (just 74 vehicles completed the race). The racers followed a route from Paris to Marseille, where boats carried them across the Mediterranean Sea to Algeria. From there, the route continued through the dunes and dust of Niger, Mali, Upper Volta (now Burkina Faso), and, finally, Senegal.

The Dakar Rally continued annually and gained popularity, reaching a peak of 688 racers in 2005. In 2008, security threats in Mauritania (Mali’s neighbor to the west) shut down the race, and it was moved to the deserts and scrubland of South America. The 2017 Dakar Rally began with 566 racers. The winning drivers came from Brazil, France, Russia, and the United Kingdom.

To compensate for negative impacts of the race on the environment, Dakar Rally sponsors donate large sums to the Madre de Dios project that works to protect the Amazon rain forest and other natural habitats of South America. Race routes avoid sensitive archaeological or paleontological sites, and strict cleanup and recycling rules ensure the integrity of the stunning natural landscapes that define the spectacle of the rally.

July 8, 2016

Tomorrow, July 9, Argentines will celebrate the 200th anniversary of the signing of their nation’s declaration of independence. President Mauricio Macri will lead Nueve de Julio (Ninth of July) ceremonies at the house in northwestern San Miguel de Tucumán where the signing took place on July 9, 1816. Other dignitaries scheduled to attend include former Spanish King Juan Carlos and leaders from several Latin American countries.

Representatives signed Argentina’s declaration of independence at the Congress of Tucumán on July 9, 1816. Credit: © Everett/Shutterstock

Earlier in the week, Argentine lawmakers and political leaders met at Tucumán to commemorate the bicentennial. Emilio Monzó, speaker of the lower house, called the gathering “an unprecedented event in the history of our country that representatives from the National Congress travel to the place where our country was born.” Senate leader Federico Pinedo, Tucumán Governor Juan Manzur, and Argentine Vice President Gabriela Michetti also attended the midweek commemoration.

The 1816 signing of the declaration of independence took place during a turbulent period in Argentina’s history—a period, in fact, before the nation was called Argentina. It was then known as the United Provinces of the Río de la Plata, and it covered only the current nation’s northern half above Patagonia. The declaration of independence also came six years after the formation of a government independent of Spain on May 25, 1810, in Buenos Aires. The area had been part of a Spanish colony since the late 1500’s.

After establishing self-rule in 1810, it took awhile to unite Buenos Aires with the various Argentine provinces. Eventually, provincial representatives met at the Congress of Tucumán on July 9, 1816, and declared their nation’s independence. The new nation had a rough go of it, however, suffering through a civil war and decades of dictatorship before the constitution of 1853 established a republic, which was renamed Argentina in 1860. The nation grew to include Patagonia in 1881.

November 24, 2015

On Nov. 22, 2015, Argentines voted for significant change. In a presidential runoff contest, voters elected opposition candidate Mauricio Macri of the center-right Cambiemos coalition. Cambiemos is Spanish for let’s change. It was the first presidential run-off in Argentina’s history. Macri defeated Daniel Scioli, the candidate of the governing Peronists, with about 51 percent of the vote. Scioli beat Macri in the first round of voting on October 25, but not with enough votes to be declared president. Scioli is a former vice president of Argentina who belongs to the Front for Victory.

Opposition candidate Mauricio Macri celebrates after winning a runoff presidential election in Buenos Aires, Argentina, Sunday, Nov. 22, 2015. Macri won Argentina’s historic runoff election against ruling party candidate Daniel Scioli. Credit: © Ricardo Mazalan, AP Photo

Macri’s election ended more than a decade of government by the Peronists, led by former President Néstor Kirchner, then his wife, President Cristina Fernández de Kirchner, since 2003. Fernández de Kirchner, who has served two terms as president, was constitutionally barred from seeking a third term. Historically, the Peronists have supported populist policies aimed at helping ordinary people. However, under Fernández de Kirchner, Argentina also has experienced high inflation, weak economic growth, and a large deficit. In addition, Fernández de Kirchner has created conflict with her public attacks on critics of the government and her confrontational stance regarding the Falkland Islands, claimed by both Argentina and the United Kingdom.

Macri, a wealthy businessman of Italian ancestry, is the mayor of Buenos Aires and a former president of the popular Boca Juniors soccer team. He ran on campaign promises to reduce the state’s control over the economy; bring new investment to Argentina; fight narcotics trafficking and political corruption; and change foreign policy, for example by strengthening ties with the United States. Although Macri has said that he will not reverse all the government’s leftist policies, his critics fear he will end social welfare programs. Scioli warned voters that Macri would introduce “savage capitalism” in government. However, Sunday’s election indicated that for many voters, Macri represented hope, a fresh start, and a chance for real change in a country with some real problems. Macri is expected to take office on December 10.

Other World Book article

      Perón, Juan Domingo

May 19, 2014

Fossils from a massive dinosaur that was longer than two tractor-trailer trucks parked end-to-end and weighed more than 14 African elephants have been unearthed in the Patagonia region of Argentina. The 95-million-year-old fossils were found near La Fletcha, about 800 miles (1,300 kilometers) south of Buenos Aires, the capital. The yet-unnamed dinosaur may have been the biggest of the big–a new species of titanosaurus, the largest of the gigantic, long-necked dinosaurs called sauropods.

Sauropods walked on four stout, strong legs, much like those of an elephant. Nearly all sauropods had a long neck, a small head, a long tail, and a huge, deep chest and stomach region. Sauropods were the largest plant-eaters, feeding on the leaves of tall shrubs and of such trees as conifers. During the Cretaceous Period, they declined in importance in the Northern Hemisphere. But they remained the dominant plant-eaters in what are now South America, India, and Africa. Other supersized saurpods include Seismosaurus and Supersaurus.

A new sauropod discovered in Argentina may have been larger than Supersaurus (above), one of the largest dinosaurs to ever walk on Earth. (World Book illustration by John Francis, Bernard Thornton Artists)

The newly discovered sauropod was an estimated 130 feet (40 meters) long, weighed 88 short tons (80 metric tons), and stood 65 feet (20 meters) tall at the hips.  (By way of comparison, Tyrannosaurus rex was about 40 feet (12 meters) long, weighed about 7 short tons (6.3 metric tons), and stood about 12 feet (3.7 meters) high at the hips.)

The Argentine and Spanish paleontologists who excavated the fossils based their estimates of its gargantuan size on the largest of the thigh bones found. About 150 bones from at least seven individual dinosaurs have been found at the site. They include 10 vertebrae (bones of the spine) from the torso, 40 vertebrae from the tail, parts of the neck, and complete legs. Scientists cannot yet say with certainty that the newly discovered sauropod is the largest dinosaur–and, therefore, the largest animal–to ever walk Earth. Fossil skeletons from sauropods are generally incomplete. In addition, sauropod tails, which accounted for much of the dinosaurs’ length, are particularly rare.

Additional World Book articles:

• Prehistoric animal
• Tyrannosaurus Rex: The Tyrant Still Reigns (a Special Report)
• Paleontology (2003) (a Back in Time article)
• Paleontology (2006) (a Back in Time article)
• Paleontology (2008) (a Back in Time article)
• Paleontology (2013) (a Back in Time article)