Dinosaurs reigned on Earth during the Mesozoic era, between 250 million and 65 million years ago (Ma). Divided into three periods (Triassic, Jurassic and Cretaceous), the Mesozoic era ended with the Earth’s fifth mass extinction, when a massive meteorite wiped out non-avian dinosaurs, ammonites, and many other life forms. This meteorite, probably about ten km in diameter per thousand billion tons, triggered a wave of energy five billion times greater than the atomic bomb dropped on Hiroshima on August 6, 1945 and 10,000 times greater that all the bombs of humanity combined. The Chicxulub impact crater located on Mexico’s Yucatan coast bears witness to this cataclysm.

During the Cretaceous period from -145 to -66 Ma, Pangaea – the supercontinent formed during the Carboniferous that included almost all the Earth’s land mass – split to form the present continents, while the Atlantic Ocean widened. Another ancient supercontinent, Gondwanaland, began to break up around 200 Ma, moving away from Africa and fracturing into Antarctica, South America, and Australia.

Although it began with a cooling at the end of the Jurassic period, the Cretaceous climate was hot and dry across the globe. The intensified volcanic activity on the oceanic ridges released large amounts of carbon dioxide, similar to the greenhouse effect, and increased land and ocean temperatures more than 10°C and 7°C over today’s temperatures by the end of the Late Cretaceous. This fiery climate supported the development of vegetation such as forests (conifers, leafy trees including fig trees, magnolias, and Platanaceae) and savannas. It also drastically influenced the existence of organisms on the territorial level (archosaurian reptiles, mainly dinosaurs, small mammals, termites and ants, Aphidoidea, Cynipidae, locusts and butterflies) and on the marine level (rays, modern sharks, fish, and marine reptiles such as Ichthyosaurs, Plesiosaurs and Mosasaurs, ammonites, marine dinosaur birds known as hesperornithiformes Foraminifera, Globotruncana, echinoderms such as starfish or sea urchins, and single-celled micro-algae called diatoms).

On the Indochinese peninsula, many traces of dinosaurs can be found in the geological formations of the Shan-Tai block, or Sibumasu, which extends over the western parts of Thailand and Malaysia, and within the Indochinese block that stretches across northeastern Thailand, Laos (excluding its northwestern part), Cambodia, Vietnam (except in the northeast, which is bordered by the so-called Red River Fault) and eastern Malaysia. The pioneering French geologist-paleontologist Josué-Heilmann Hoffet collected the first fossils in the latter block, at the level of the “Upper Sandstones” formation in Laos in the Savannakhet Basin, whose strata date back to the Aptian-Albian stages of the Early Cretaceous (between -100 and -125 Ma).

Assigned to the Geological Survey of Indochina based in Hanoi, Hoffet studied the continental formations of Lower Laos. In 1936 near Ban Tang-Vay, he found the first dinosaur bones ever discovered in Laos, as well as the remains of turtles and crocodiles, which the locals describe as the remains of “sacred buffaloes.” In 1942, Hoffet published a description of titanosaurid bones found in the Senonian of Lower Laos, discovering two new species: the titanosaurus of Muong Phalane (Titanosaurus falloti), an imposing herbivorous, four-legged dinosaur; and the hadrosaure Mandschurosaurus laoensis, a smaller herbivorous, duck-billed bipedal dinosaur. Both lived towards the end of the Cretaceous, around -80 Ma.

When Laos reopened its borders in 1990, the paleontologist Philippe Taquet, then director of the National Museum of Natural History (MNHN) in Paris, flew to Vientiane and Savannakhet to continue Hoffet’s work as part of a Franco-Laotian mission to find the site of Ban Tang Vay. In conjunction with work carried out in Thailand, the mission revealed several fossiliferous deposits of the Early Cretaceous, including bones and footprints of sauropods, theropods, ornithopods as well as the remains of turtles, freshwater bivalves, and fossil plants. The sauropods were attributed to a new species known as Tang-vayosaurus hoffeti, or Tang Vay lizard; together with the genus Phuwiangosaurus sirindhornae found in Thailand, they are the only known sauropods in Southeast Asia.

Other international and Franco-Laotian campaigns followed, including Dinosavan: Dinosaurs of Paradise, led by the team of paleontologist Ronan Allain of the MNHN in Paris, supported by the National Geographic Society, and in association with Thiengkham Xaisanavong’s team from the Dinosaur Museum in Savannakhet. New specimens were discovered, notably the psittacosaurus, a parrot-billed dinosaur belonging to the group of ornithischians (bird-footed dinosaurs) of the super-family of hadrosauroids – a bipedal and herbivorous species the size of an antelope also found in China, Mongolia, and Thailand. The psittacosaurus seems to have lived only in present-day Asia, as it was probably cut off from the rest of the world in the Early Cretaceous. Also revealed were remains of undetermined iguanodonts and theropods, including the first definitive record of the family Spinosauridae in Asia (found in 2012), a new taxon named Ichthyovenator laosensis – literally “Laotian fish hunters” – some eight to ten meters long, with crocodile-shaped skulls and a sinusoidal dorsal veil of about 50 to 60 cm overhanging the right rear, the pelvis, and the front part of the tail. Spinosaurs are among the largest and most specialized carnivorous dinosaurs. Also, close cousins of the siamotyrannus of the family Sinraptoridae, known as “Chinese robbers” and discovered in Thailand, are also suspected to have lived in Laos.

In sum, the Early Cretaceous fauna of Europe and Southeast Asia share many similarities, including certain families of dinosaurs, crocodiles, pterosaurs, mammals, and turtles exclusively known on these two continents at the end of the Cretaceous era.

Some of the discoveries are exhibited at the Savannakhet Dinosaur Museum, a place to visit after a trip to Champassak, the town that hosts the UNESCO pre-Angkorian archaeological site of Wat Phou, or after a cruise on the mighty Mekong River between the so-called 4,000 islands, a river archipelago crowned by an infinite number of large liquid islets perched among the rapids; or from Luang Prabang, a bewitching capital with an exceptional architectural heritage

© Illustration Credit: Pierre Lavaud aka Mazan

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February and March 2021 mark the 50th anniversary of the major Vietnam War operation known as Lam Son 719, and Secret Indochina is commemorating the event with a look back at the operation.

Lam Son 719, or Campaign of the RN 9, was a large-scale operation carried out by the South Vietnamese Armed Forces (ARVN) between February 8 and March 25, 1971. It took place in central Laos, along the Middle and Lower Sepon River between Lao Bao and the town of Sepone (Tchepone). The campaign’s objective was to halt a potential offensive by the North Vietnamese Army (PAVN) against central and southern Vietnam. The operation lasted 45 days and involved about 17,000 ARVN soldiers. They were supported by approximately 10,000 US troops, including soldiers from the US Army 24th Corps and the First Airborne Division for air operations. The largest heliborne operation of the Vietnam War, Lam Son 719 involved considerable resources, including 649 helicopters. It eventually collapsed due to the inability of the South Vietnamese leaders to face strategic realities.

Between 1959 and 1970, the Ho Chi Minh Trail was the key logistical artery for PAVN and Viet Cong military operations aimed at overthrowing the South Vietnamese government. From 1966 on, more than 600,000 men, 100,000 tons of food, 400,000 weapons, and 50,000 tons of ammunition were transported via the maze-like trail across forested dirt tracks and rivers from North Vietnam through central-eastern Laos and into the southern regions of Vietnam. The Americans engaged in various efforts to target the trail, including creating a secret Hmong army commanded by General Vang Pao and using an entire arsenal of sophisticated weaponry.

In 1970-1971, signs of strong logistical activity multiplied in southeastern Laos, heralding a large-scale offensive. In the face of this threat, the South Vietnamese and their American advisors decided to undertake Operation Lam Son 719.

The first step in Lam Son 719 was Operation Dewey Canyon, which aimed to prepare and clean access to the Laotian border south of Khe Sanh and the border post of Lao Bao, as well as reopen access to the RN 9 road that had been abandoned since 1968. On the morning of January 30, armored elements and infantry of the 5th Infantry Division moved westward on the RN 9. Engineers installed nine bridges, while infantry elements were taken by helicopter directly to the Khe Sanh area. On February 5, the RN 9 was secured up to the Laotian border and the Khe Sanh airport rehabilitated. At the same time, the 101st Airborne Division began a diversionary operation in the A Shau valley to draw the attention of the PAVN away from Khe Sanh.

Once the Khe Sanh rear base was established, the real offensive began on February 8. After a massive preliminary artillery bombardment and 11 B-52 Stratofortress missions, the incursion began with an offensive led by an ARVN armored and infantry task force of 4,000 men, consisting of the 3rd Armored Brigade and the 1st and 8th Airborne Battalions. The 39th Ranger Battalion was heliborne to various landing zones (LZs), also called landing sites (LS), lima sites, or fire bases, as appropriate. The US provided logistical, air, and artillery support to the operation, as its land forces were prohibited by law from operating on Laotian territory. At the same time, American combat helicopters attacked various targets, generating huge forest fires.

The offensive continued along RN 9 and the axis of the Sepon River (Xé Pon, Se Pon), above which other support LZs were established (30, 31, Sophia, Liz, Delta, Hotel, Hope, Lolo, Don, Ranger North, and Ranger South). Localized and sporadic fighting ensued, with AH-1G Cobra helicopters intervening in all engagements, as the terrain was almost impassable to untracked vehicles. Various North Vietnamese bases of the 308 Division were captured, notably south of LZ Don on February 12. B-52 raids supported the advance and burned entire areas.

North Vietnam’s response to the incursion was gradual; 36,000 men were rounded up and directed to the area. The method chosen by the PAVN to stem the offensive was first to isolate the LZs using artillery, mortar fire, 122 mm and 130 mm rockets supplied by the Soviets, and then via massive ground attacks supported by T-55 tanks. Counterattacks began on February 18, notably on the Ranger North and Ranger South LZs. Through February 25, a series of fierce fights took place around the LZs and the border zone. Despite the massive USAF intervention, however, the South Vietnamese were forced to gradually retreat back to their point of departure (Khe Sanh and the coast).

For the North Vietnamese, Route 9 – Victory of South Laos was considered a success. The PAVN claimed to have eliminated 20,000 enemies, destroyed 1,100 vehicles (including 528 tanks), demolished over 100 pieces of artillery, shot down 505 helicopters, and captured more than 1000 prisoners. The military expansion of the Ho Chi Minh Trail to the west, which had begun in 1970, accelerated rapidly, while the Laotian royalist troops withdrew towards the Mekong. Another result of the operation was the Politburo’s decision to launch a major conventional invasion of South Vietnam, a path to final victory.

Over the course of the operation, American helicopters carried out more than 160,000 sorties. Nineteen American pilots were killed, 59 wounded, and 11 went missing. The tactical aviation carried out 8,000 sorties during the incursion and dropped 20,000 tons of bombs and napalm, while B-52s carried out 1,348 sorties and dropped 32,000 tons of bombs.

The PAVN reported 13,336 soldiers Killed in Action (KIA) out of an estimated 22,000 combatants engaged in the area of operations. Only 69 enemy soldiers were declared prisoners of war. The ARVN armed forces reported 1,480 dead, 5,420 wounded, and 691 missing out of a field force of about 17,000. The American forces suffered a staggering number of rotorcraft losses: 108 helicopters were destroyed and 600 damaged. Of the approximately 10,000 American soldiers engaged in the operation, 215 were KIA, 149 WIA (wounded in action) and 42 MIA (missing in action).

Within the framework of Secret Indochina’s special programs on the American secret war in Laos, it is possible to find various LZs established on the axis of the RN 9 in the direction of Tchepone (Sophia, Liz, Delta, Hotel, Hope and Lolo). As with the Indochina Wars, the battles of the Vietnam War often took place in regions or sites of wild and disturbing beauty – remote primary forests of the Annamese chain, deltaic or coastal regions, minority lands, for example. Today, some have become national parks or nature reserves associated with historical or cultural modules. This is the case for the northern part of the Lam Son 719 operation zone, which is located in the southern foothills of the Hin Namno NBCA, a national park in central Laos notable for its sumptuousness and for the fact that it is the western extension of the world-famous limestone massif of Ke Bang - Phong Nha