A very short history of Paleobotany

"There are so many plants on the earth, that there is a danger to thinking them trivial...[]...What a marvellous cooperative arrangement, plants and animals each using the others waste gases, the whole circle powered by abundant sun light. But there would be carbon dioxide in the air, even if there were no animals. We need the plants much more then they need us."

Carl Sagan in "Cosmos", ep. 2 "One Voice in the Cosmic Fugue"

Fig.1. A modern fern blade compared to a fossil of the Carboniferous (almost 300 Ma) from Southern France.

Plant fossils are possibly the first petrifactions recognized as the remains of once living organisms - many fossils species still resemble extant species and it was therefore straightforward to compare and match them together.
Already in 1699 the English naturalist Edward Lhwyd (ca. 1660-1709) depicted various fossil plants in his catalogue of the English fossil titled "Lithophilacii Britannica ichnographia". Also Carl von Linné (1707-1778) studied and published some notes about plant fossils hosted in the cabinets of curiosities of Swedish noblemen.
The oldest publication dealing almost exclusively with plant fossils is however the "Herbarium diluvianum" by the Swiss scholar Johann Jakob Scheuchzer, published in various edition in 1709 and 1723.

Fig.2. Plate from J.J. Scheuchzer´s opus magnus "Herbarium diluvianum" (1709-1723).

Scheuchzer published his studies and observation of many fossils plants coming from the English Carboniferous, the Permian of Germany and the Swiss Cainozoic, including plant casts found in travertine. He argued that these imprints were once living plants like recent ones that became buried in sediments by the biblical flood. His was so convinced of the similarities of fossil to modern plants that he even tried by phenology to determinate the month when the flood occurred.

Unlike bones, shells and ammonites, collected and studied avidly by amateurs, paleobotany was since its early origins dominated by professional scholars - the identification of fossil plants requires apparently more skills and profound knowledge in modern botany, abilities or interests not encouraged enough in all times?

Fig.3. Plate from Caspar von Sternberg´s "Versuch einer geognostisch-botanischen Darstellung der Flora der Vorwelt" (Attempt to a geognostic-botanical representation of the flora of the ancient world) (1820-1838), showing the "bark" of an extinct Lepidodendron-"tree" related to the modern Lycopsids.

In 1804 the German Geologist and Palaeontologist Ernst Freiherr von Schlotheim (1764-1832) published a description of Permian plants "Beschreibung merkwürdiger Kräuter-Abdrücke und Pflanzen-Versteinerungen" (Description of curious imprints of herbs and plant-petrifactions), where he adopted on the fossil plants the systematic-system developed by Linné and compared their ecology to modern plants, establishing finally the principles of modern Paleobotany.
Important contributions to botany of fossil plants and pollen grains and there use in stratigraphy came from the French geologist Alexandre Brongniart (1801-1876 - with Cuvier one of the first to draw startigraphic profiles in Europe) with his "Histoire des vegetaux fossiles, ou recherches botaniques et geologiques sur les vegetaux renfermes dans les diverses couches de globe"(1828-1838).

Fig.4. Plate from A. Brongniart´s "Histoire des vegetaux fossiles" (History of fossil plants) (1828-1838).

After the first general works on paleobotany surprisingly fast more specific research on single formations, geographical areas or plant groups was published, for example the German Heinrich Robert Göppert (1800-1884) studied the Tertiary brown coal deposits and the Austrian physician Franz Unger (1800-1870), after becoming professor for paleobotany in Graz and Vienna, studied the coal deposits of Styria. In his "Iconographia plantarum fossilium" he compares the fossil flora with the forests of Indonesia, South America, the Caribbean and Mexico, recognizing that the plants indeed can be used to reconstruct the climate of a tropical past - it is no wonder that geologist Henry de la Beche (1796 -1855) collocated "Professor Ichthyosaurus" in a tropical jungle with palm-trees and gigantic ferns.

Fig.5. Plate from H.R.Göppert´s "Die Tertiärflora auf der Insel Java" (Tertiary flora of Java) (1854).

To be continue...

Online Resources:

ROBERTS, B.F.; SHARPE, R. & WATT, H. (): Edward Lhwyd. (Accessed 09.06.2011)

8, June 1783 : The Laki eruptions

"The sun begins to fade away, the continent sinks into the sea:
The bright stars, they disappear from the sky:
Smoke hurls up from the burning fire and destroys the world;
Gigantic flames reach into the sky."
The end of the world according to the Icelandic collection of sagas "Völuspa" (13th century)

Fig.1. Hand coloured copper engraving of Iceland and some of its volcanoes, from the Physical Atlas by Heinrich Berghaus (1838-48).

Volcanoes are nothing unusual on Iceland, but after three weeks of earthquakes on 8, June 1783 begun an eruption that is today considered the second largest in Iceland's historic records.
In six months estimated 14 cubic kilometre of lava poured out from a total of 135 newly opened craters near the old crater of Laki (Lakagigar is a single mountain, Laki the chain of volcanoes), aligned along a more than 24 kilometre long rift southwest of the Vatnajökull. The lava inundated a lake and two rivers, vaporising all the water and flowing along the valleys in direction of the Atlantic Ocean. In the end the lava covered estimated 2.500 square kilometre of land.
The shepherd Jón Steingrímsson described the eruption as follows:

"First the earth swelled up with tremendous howling, then suddenly a cry that shattered it into pieces and exposed its guts, like a rabid animal tears apart it prey.
From the smallest holes in the lava flames and fire erupted. Great blocks of rocks and pieces of grass were thrown high into the air in indescribable heights, from time to time strong thunders, flashes', rays of sand and light or dense smoke occurred... Earth trembled incessantly. …how terrible it was to see, such signs of an angry god...it was time to confess you to the lord."

More than 9.000 people living in villages overrun by the lava and poisonous gases and ash rain were buried and burned alive or perished of asphyxiation.
The ash poisoned the land and the sea of Iceland, killing half of the cattle's population, a quarter of the sheep's and horses, on the fields the crops died off and in the sea the fishes were killed - even in areas not directly hit by the eruption people begun to starve in the years 1783 to 1784.
Twenty thousand people, one-third of the population of Iceland, were killed directly or indirectly by the eruptions of Laki.
The ash blow up into the atmosphere influenced the climate of the northern hemisphere, and possibly by causing famine influenced even the history of Europe (the French Revolution in the years 1789-1799 was also triggered by high food prices).

Bibliography:

BOER, de J.Z. & SANDERS, D.T. (2004): Das Jahr ohne Sommer. Die großen Vulkanausbrüche der Menschheitsgeschichte und ihre Folgen. Magnus-Verlag, Essen: 269
DAVIS, L. (2008): Natural Disasters. Facts on File Sience Library. Infobase Publishing: 464

Online Resources:

HARRINGTON, R. (08.06.2011): On This Day: the Laki eruption begins, 1783. (Accessed 08.06.2011)

The history and geology of the first Italian dinosaur: Scipionyx samniticus

"In geology we cannot dispense with conjectures: [but] because we are condemned to dream let us ensure that our dreams are like those of sane men-e.g. that they have their foundations in truth-and are not like the dreams of the sick, formed by strange combinations of phantasms, contrary to nature and therefore incredible."

"Introducione alla Geologia" (1811), by Scipione Breislak

The fine-grained, greyish to yellow, cherty limestone surrounding the area of the small village of Pietraroia (or Pietraroja in the Italian province of Benevento/Campania) was in the past a popular rock used widely in construction works, but for centuries it provided also more peculiar treasures - exceptional well conserved fossils forming an important fossil-Lagerstätte of the Cretaceous.
The Italian physician and naturalist Nicolo' Braucci da Caivano (1719-1774) mentions briefly the fossils in his work "Historia Naturale della Campania Sotterranea" (1770):

"...quivi dentro le valli lacerate, erose dai torrenti delle acque piovane, si scoprono sassi con l'impronta di molti generi di pesci, e specialmente di sarde." (source)
"There [in the Matese Massif] inside the valleys, eroded by the streams of rainwater, you will discover rocks with the imprints of many kinds of fish, especially sardines."

However the first naturalists to describe more in detail the fossil fishes found on the surface of the limestone layers was the Italian philosopher, theologian and physicist Scipione Breislak (1750-1826) in his book about the geology of Campania, with the title "Topografia fisica della Campania", published in 1798 he wrote:

"Sopra Cerreto sorge l'alta montagna di Pietra Roja che è una delle cornate del Matese, molto interessante per i prodotti che presenta. Questa montagna in alcune parti è composta da pietra calcarea scissile con impressioni di pesci. La durezza però dello schisto e la molteplicità delle venature spatole che s'intersecano in molte direzioni, fan sì, che con difficoltà se ne possano avere de' belli esemplari, né sono giammai di quella precisione e bellezza che si osserva ne' pesci fossili di Bolca".
"Above Cerreto rises upwards the mountain of Pietra Roja..[]..very interesting for some features it presents. This mountain in some parts is composed of cleaved limestone with the impressions of fishes. However the hardness of this shale and the multiplicity of the crystalline fissures, which intersects in many directions, make it hard to recover some good specimen, they are never as well preserved and beautiful as the fossil fishes of Bolca."

In the years 1853 to 1864 the geologist Oronzo Gabriele Costa (1789-1867) published various volumes of his "Paleontologia del Regno di Napoli", where he in magnificent prints depicted the fossil fishes of the "fishes-bearing limestone of Pietraroia", name that was later also adopted to designate the geologic formation of Pietraroia.

Fig.2. Impression of articulated fossil fish as found in the limestone-Lagerstätte of Pietraroia, the tail can be seen above the pencil.

Fig.3. Disarticluated skeleton in typical reddish-brown preservation.

The formation of Pietraroia, also Pietraroia Plattenkalk, consists of a succession of thick bedded limestone and dolostone, with embedded greenish layers of marl and rare fossils in the lower part, and 2-25cm thick bedded bituminous limestone and dolostone whit chert-layers and a rich variety of vertebrate fossils in the upper part.

Fig.4. Former quarry with outcrops of the vertebrates rich Plattenkalke (upper part of the Pietraroia-formation), today included (in theory) in the protected Geo-Park of Pietraroia. The fossils are found on the limestone surface in the foreground, the former bottom of an ancient sea basin.

The macrofossils found in this formation comprise ammonites, crustaceans, a rich variety of fishes, crocodiles, three species of (presumed) lizards, one species of amphibian and one species of larger vertebrate.
In fact the Plattenkalk of Pietraroia became worldwide known to the paleontological community in 1998, when a nearly complete skeleton of a dinosaur was described by the Italian palaeontologists Cristiano Dal Sasso and Marco Signore in an article in the prestigious journal "Nature" and the new species named Scipionyx samniticus.

The described fossil was extraordinary; a nearly complete and articulated skeleton of a small (23cm long) bipedal dinosaur, lacking only parts of the tail and some bones of the hind legs, additionally in the body cavity there were structures interpretated as imprints of the inner organs; it was in fact so photogenic that Scipionyx samniticus, or Ciro as the fossil was nicknamed by an Italian newspaper that financed the research of the fossil, made it on the cover of the actual edition of Nature.
At the time it was one of the best preserved theropods known to science. The genus "claw of Scipio" is dedicated to Scipione Breislak, who first described the locality, the species name derives from the ancient Latin name for the region of South Italy of Samnium, which comprised modern Campania.

The exact circumstances of the discovery and description of the fossil of Scipionyx is an intriguing story. It must be said that in Italy the active search for fossils is in practice prohibited, the legislation concerning the matter is however vague and requirements for the legal custody of fossil confusing. Whoever found and collected the fossil was at the moment and in theory committing a crime against the Italian state…

- One version of the story of the recovery of Scipionyx claims that it was found in 1979 by an anonymous boy who handled the fossil over to an amateur palaeontologist, who did not recognize it as dinosaur and only in 1993 contacted the museum of natural history museum of Milan to determinate the species.

- Another version claims that the fossil was discovered by accident by two tourists of Milan visiting the village of Pietraroia. They took the fossil with them, but only in 1993 and after the release of the movie "Jurassic Park" they recognized it as possible dinosaur and handled it over to the authorities of the natural history museum of Milan.

- A third versions claims that an anonymous palaeontologist obtained the fossil from a collector with contacts to the black market, and finally handled it over to the museum in Milan.

- The official version, published in most reports and books, attributes the discovery to the amateur fossil collector Giovanni Todesco from Verona. Todesco during a journey in South Italy visited the site of Pietraroia and hoping to collect some fossils he examined a slab of unusual shape in a dump of rocks used for the construction of a new street. Observing more carefully the rock he noted imprints of bones covered by a thin layer of sediments. He took the slab home and tried to remove the thin layer of sediments, but soon abandoned this arduous task and the presumed bird-fossil became forgotten for years.
Only in 1992 Todesco contacted the palaeontologist Giorgio Teruzzi, who finally recognized it as dinosaur and contacted the rare Italian dino-experts.

Scipionyx and the Lagerstätte of Pietraroia is not only an important paleontological discovery, but was useful also for geologist. The taphonomy of Scipionyx and the other discovered vertebrates helps to reconstruct the environment in which they lived and has important implications of the paleogeography of the Italian peninsula and the Tethys Ocean.
The limestone consists mostly of fragments of foraminifers and spicule of echinoderms, reworked algae and clastic deposits. Such sediments were produced in a biologically active zone were enough sun light and nourishment are available. However the distinct stratification and the presence of bitumen in the Plattenkalke points to an environment without currents, which could disturb the deposition of sediments, and the lack of oxygen, inhibiting the biologically breakdown of organic matter.
Also the presence of terrestrial vertebrates on the surface of the layers shows that these are single sedimentation-events, probably the sediments engulfed very fast the remains of dead animals and conserved them fully articulated.
The presence of larger animals like reptiles and amphibians in the fossil record, depending on the availability of freshwater, proves the former presence of islands or large areas of land covered with vegetation and with large rivers - interestingly in the geologic record there are no such direct hinds and until some decades ago the Tethys Ocean was therefore reconstructed as a large, monotonous and shallow sea.
The modern reconstruction of the environment of Scipionyx includes an archipelago of islands scattered in the Cretaceous Tethys Ocean, large enough to sustain populations of endemic dinosaur species and surrounded by lagoons with a high biologic productivity.
Submarine channels connected the deltas of rivers coming from inland of the islands to deeper basins in the sea with reduced oxygen content and low biologic activity. From time to time turbidity currents descended these channels, carrying with them the carcasses of animals drowned in the rivers or in the lagoon and embedding them in fine grained sediments, protecting them from currents, decay and scavengers.

Soon after the publication and description of Scipionyx and the increased interest in the Lagerstätte of Pietraroia it was attempted to protect the area and encourage it as local touristic attraction with the foundation of an Geo-Park, until 2001 also field campaigns to study the geology and recover other fossils were initiated, but finally the money run out and the area was soon vandalized, displays and structures damaged and even entire fossils stolen.
The in 2005 new build museum -the Paleolab- was unfortunately until 2007 mostly an expensive media spectacle open to the public only two days in a week, with (at the time) mostly fake fossils on display, promised financing never arrived to Pietraroia and the park... in the moment the Italian authorities decided to put Ciro here... - however there is still hope and rumours about a monograph dedicated to Scipionyx...

Fig.6. The PaleoLab museum with the protected (but not guarded) park in the background.

Bibliography:

BARBERA, C. ; SIGNORE, M. & LA MAGNA, G (1999): International meeting on Scipionyx samniticus dinosaur, Telese Terme, 25-27, 1999 - Guida all'escursione e abstracts.
CARANNANTE, G.; SIGNORE, M. & VIGORITO, M. (2006): Vertebrate-rich Plattenkalk of Pietraroia (Lower Cretaceous, Southern Apennines, Italy): a new model. Facies 52: 555-577
DAL SASSO, C. & SIGNORE, M. (1998): Exceptional soft-tissue preservation in a theropod dinosaur from Italy. Nature 392 (26, March 1998): 383-387
DAL SASSO, C. & BRILLANTE, G. (2001): Dinosauri italiani. Marsilio Editore, Venezia: 256
DALLA VECCHIA, F.M. (2003): Dinosaurs of Italy. C.R. Palevol 2: 45 - 66 (book-cover used as introduction of the post)
SIGNORE, M. (2004): Sample excavations in Pietraroja (lower Cretaceous, Southern Italy) in 2001 and notes on the Pietraroja palaeoenvironment. PalArch vertebrate palaeontology Vol.2 (2): 13-22

Cowboys, Dinosaurs and Eohippus: The Valley of Gwangi (1969)

"The Valley of Gwangi" (1969) is considered one of the most important productions in the history of the genre of prehistoric movies and one of the best works of special effects artist Ray Harryhausen.

The story of Gwangi is based on a script written by the former teacher of Harryhausen, special effects pioneer Willis O'Brien, but only several years after the first drafts the producer Charles H. Schneer decided to adapt it into a very peculiar movie.
Harryhausen was hired for the special effects and the animation of the monsters featuring in the movie. He finished the animations of his creatures on 7, October 1968, after more than 400 individual shots in stop-motion technology - the highest number used for a movie at the time.



Fig.1. Ray Harryhausen is best known for his stop-motion creatures featured in various movies and genre: adventure, science-fiction, fantasy and in a certain manner even science. Between 1938 and 1940 Harryhausen worked on his first preliminary project called "Evolution".

Until January 1969 the proposed title for the film was "The Valley Where Time Stood Still", but to the production company (Warner) this seemed to long and complicated, and it was changed, not without bitter protests to "The Valley of Gwangi".
The movie was releases almost at the end of the golden age of monster movies in the sixties and seventies, the general public had lost interest in the genre and it was therefore hoped that the particular storyline of the movie would attract again fans of monster-, but also adventure-, catastrophe- and western- movies.

Apart the stunning special effects, the film is notable that it mixes parts of the classic western genre with parts and elements of the classic film about dinosaurs and other prehistoric creatures.
The film is set in rural Mexico (and was filmed in Spain) of the early 19th century. In the middle of the desert Professor Bromley (I wonder if the name is a tribute to Dr. Robert Broom) discovers a sensational fossil: a slab with human footprints along the trackway of a three-digit horse of the extinct genus Eohippus.
Later the local circus receives a strange animal: a small horse with three digits on every leg, named El Diablo. In an attempt to discover the valley from which the horse came the palaeontologist first kidnaps and then follows the animal to the entrance of the forbidden valley. Here they meet the most terrible predator - Gwangi himself, a terrible Tyrannosaurus ... Allosaurus, animals that Harryhausen, as he himself admits, confused when he created the doll for the movie.

29, May 2006 : Birth of the mud volcano of Sidoarjo

Five years ago, at 5 o'clock in the morning of May 29, the inhabitants of the village of Sidoarjo in East Java witnessed the beginning of the eruption of a mud volcano - and still today every day nearly 30.000 cubic metre of gasses, water and mud emerge from the underground.

Already in 1778 the Italian physicist Alessandro Volta examined the methane gas outpouring from the mud volcanoes of Pietramala near Florence, from time to time this gas ignited producing up to 2 meter high natural torches.
The German explorer Alexander von Humboldt described mud volcanoes he encountered near the Columbian village of Turbaco during his expedition to South America in the years 1799 to 1804 - even if he exaggerated the height with three to four meters (the mounds are approximately one meter high).

Fig.1. The mud volcanoes near the Columbian city of Turbaco, after HUMBOLDT & BONPLAND (1804): Personal Narrative of Travels to the Equinoctial Regions of America, During the Years 1799-1804.

Today worldwide more than 1.100 mud volcanoes are recognized, located on continental shelves but also on continents.
There are various mechanisms that can cause the eruption of mud from the underground, whereby only the last two are regarded as true mud volcanoes, the rest as mud pots.

- Through magmatic activity heated gas or groundwater, that circulating carries with it loose or reworked sediments

- Liquefaction effects during an earthquake.

- Overpressured groundwater, fluids, gas and sediments in sedimentary basins, like a cap impermeable rocks can prevent underlying sediments to escape, as soon as this cap is damaged or removed water begins to rise to the surface.

- Cold methane gas or other fluids escaping from the underground and transporting sediments.

However the mud volcano of Lumpur Sidoarjo ("mud of Sidoarjo"), abbreviated to Lusi, is unique as probably the only artificial mud volcano in history. It erupted up to 180.000 cubic metres mud per day but until 2011 this amount decreased to 30.000 cubic metres per day, however only the construction of dams limited the extant of the mud flow to 7 square kilometres in 2008 - 30.000 people had to be evacuated and 11 people were killed in the explosion of a submerged gas-pipeline.



The cause of the Lumpur Sidoarjo is still controversial. In March 2006 the Indonesian oil company Lapindo Bantas started a drilling campaign 200 meter distant to the future eruption site. The company denies a direct connection to the drill operations and the eruption and affirms that an earthquake and reactivation of an underground fault system triggered the flow of overpressured gases and groundwater from a reservoir in carbonate rocks into the overlying clays.
Some independent research (DAVIES et al. 2007) blames the company to have not adequately coated the borehole. It collapsed in a depth of 1.100 meters after encountering the carbonate reservoir, the growing pressure crashed the surrounding impermeable clay rocks, therefore enabling gas and water to reach the surface and feed the mud volcano.

Fig.2. Schematic three-dimensional model of the Lusi mud volcano according to DAVIES et al. 2007, the research team proposed that an inadequate coating of the bore hole caused fractures in the surrounding rocks, causing overpressured fluids to push to the surface. A legal investigation concluded however that the drill operations were carried out according to standard procedure, the charge of negligence by oil company Lapindo Bantas was therefore rejected.
According to the spokesman the company states that the drill operations were carried out according to standard procedure, the legal case and especially the payments of compensation proceed very slowly and since 2010 legal actions against the company have stalled.

Bibliography:

DAVIES, R.J.; SWARBRICK, R.E.; EVANS, R.J. & HUUSE, M. (2007): Birth of a mud volcano: East Java, 29 May 2006. GSA Today Vol. 17(2): 4-9
HUMBOLDT, von A. & BONPLAND, A. (1804): Personal Narrative of Travels to the Equinoctial Regions of America, During the Years 1799-1804.

A geologist riddle #18

Less a riddle than a preview of the subject of the posts to come:

Five million years of terror: Quatermass and the Pit (1967)

In many science-fiction films the adversary or monster is inspired by prehistoric creatures, dinosaurs are the most popular, but sometimes also mammals and their "derivatives" play a role. The classic monster movie has a quite predictable storyline: men enter and find a place not intended to be explored, awaken so the monster, the scientist explains what it is (even to those who are watching the film) and in the end the hero and we discover how to kill it ...
The animal, and especially a "primitive" creature, is used in movies as a powerful symbol for our subconscious emotions and irrational behaviour, it represents the most primitive instincts of survival - nourishment and sexual reproduction - that are in modern men controlled (maybe even suppressed) by rationality and society.

"Quatermass and the Pit" was in origin a black and white science-fiction/horror TV-serial broadcasted in 1958 and 1959. The story based on a script by Nigel Kneale was later adapted by the British Hammer Film Productions (a company notoriously known for its B-movies) to a movie with same title (1967). Curiously in the U.S. the film was released under the title "Five Million Years to Earth" and in Germany "Das grüne Blut der Dämonen" ("The green blood of the demons", probably influenced by one autopsy scene).
The movie story follows on a first glance only loosely the classic monster story and uses an intriguing variation of the monster as symbol of primitive behaviour.



During construction works in London bones and skulls were uncovered, the anthropologist Dr. Roney discovers the fossils are of a particular breed of primate, much older than all the genera previously known to science.
Meanwhile the archaeological survey is interrupted by what appears to be the discovery of an unknown bomb-rocket of World War II, strangely embedded in the same geological strata as the fossils. The army is informed and General Breen seeks the aid of rocket scientist professor Quatermass. He will soon discover the terrible truth: the supposed rocket is an alien spacecraft. The hypothesis presented by the scientists: 5 millions of years ago a superior race of Martian insects tried to create a race of slaves from primitive monkeys, bursting the evolution of mankind. But before the aliens succeeded in their plan they annihilated themselves in a terrible eugenic war in a distant past.
In fact the reconstruction, based on the fossils and modelled in an extraordinary short time interval by Dr. Roney, shows a giant monkey with a big head, the classic missing link between man and animal (even Piltdown man is mentioned in the technobabble of some scenes of the TV-serial) in accordance to the classic "ladder of evolution" of man. The reconstruction with a large brain resembles also a bit to much modern humans, according to the real fossil record five million years the genus Australopithecus would be a more realistic approach, a bipedal primate with not to unusual characteristics in cranial volume.

In contrast to a classic monster movie in Quatermass and the Pit the discovered fossils remain however dead - there is no physical reanimation and a rampage of classic ape-men trough London. But the discovery of the ancient spaceship has started by telepathic influence also a self-destruction program in the genes of the descendants of the first ape-men - We are the monsters! By following the most primitive instinct and survival of the strongest humans begin to kill each other, like the Martian million years ago.
The movie also cites and shows in form of the war that destroyed the aliens the dangers of a worldwide nuclear threat and armament - a common topic in monster movies of the sixties and seventies. Interesting the decision to gave the Martian the aspect of locusts (but the comparison of the sorcerer of Les Trois Frères is farfetched), maybe to represent the human behaviour of colonizing and overexploiting new land ?

Quatermass and the Pit is not the classic monster movie of the sixties. The first half builds up suspense and then it develops from a science-fiction story to a ghost-horror movie, even with the classic demonic possession scene. The Martian technology is capable to control human minds, taking from us our personality transforming us in a single mob - also the attacks comes from the most unsuspected side, the common people on the street.
It's surely one of the better and more serious Hammer films.
The idea that life on earth, especially the rise of man, can be explained by the intervention of aliens is still used in science fiction today (a recent example is the film "Mission to Mars" in 2000) - ironically that some authors copied this idea even for their pseudo-serious books about Paleoseti in recent years.