Bandersnatch, Beetle, and Bacterium



Bandersnatch, Beetle, and Bacterium (fig. 1) Bandersnatch grassbag, Neotitanosaurus halletti (Sub-Saharan Africa) The mighty bandersnatch grassbag is a walking fortress of flesh, the biggest living terrestrial animals on Spec. The largest recorded specimen measured 23.7 metres from snout to tail-tip and probably exceeded the 30 ton-mark when fully laden with fat reserves. Such titans are rare, however, with the majority of adults in the 14 to 18 metre (12-20 ton) range. Reaching sexual maturity at only nine metres, no other dinosaur has such a size-disparity between breeding individuals of the same population. A healthy adult has no natural enemies, but may still succumb to fire, drought and intraspecific combat.Bandersnatches inhabit grassland, savannah and bush steppe throughout sub-Saharan Africa and show a distinct preference for tall, fibrous grasses, especially the rattlegrasses of the genus Dinosaccharum. These impressive annuals can reach over 2 metres in height with tough stems up to 10 cm in diameter. They grow with astonishing speed after the rains and can recover rapidly after fire and all but the most intensive of grazing.

The stems of rattlegrass quickly become infested with the larvae of the rattlegrass beetle (Coleagnathus drhozi) whose eggs fill the soil and the dried husks of last year's pasture. Within 2 weeks of hatching, these grubs pupate into mouthless adults, which mate, lay more eggs and die. These eggs hatch into more grubs, continuing the cycle throughout the wet season. Rattlegrass larvae feed on the continually regenerating stem tissue, molds and the carcasses of the adults. However, they will also voraciously attack and consume other insects, rendering their host plants largely immune to more harmful pests, such as locusts.

The grasses (and their insect residents) die off once conditions become drier. As they sway in the wind, the rattling of empty pupae and carapaces within the hollowed out stems of the browning grass gives rise to their common name.During the wet season, solitary male badersnatches along with herds of females and young adults plod across the fields of rattlegrass. They crop the stems with their chisel-like teeth, consuming a single plant down to an inch from the soil in one or two great bites. The protein obtained from the numerous ingested beetles probably accounts for the bulk of the nutritional value and the sauropods often target mature, well-bored out plants with a large grub population in preference to seemingly more succulent stands that have recently regenerated.

Like other sauropods, bandersnatches lack molars and do not chew their food. Instead, they pass the grass (and unfortunate beetle grubs) directly into their enormous crops, where rocks the size of a man's fist grind the high-silicate plant material into an easily digestible paste which then pass into an incredibly long gut.

Once the sauropod has extracted what nutrients it can from it, the vegetable mix then encounters yet another remarkable example of the symbiosis that helps to nuture the grassbags' food supply. The huge colon of every adult bandersnatch harbors a thriving culture of Saurorhizobium bacteria, similar to the Home-Earth Rhizobium that lives in the roots of legumes. These bacteria metabolize the dinosaur's excreta, fixing nitrates and making the dung a veryrich fertilizer for future plant growth.

Each bandersnatch drops more than a tonne of steaming faeces each day, which attracts hordes of dung beetles up to the size of tennis balls. Within two days of droppage, a sauropat over two metres across will be completely buried by the actions of these insects. In doing so, they transport countless grass seeds and beetle eggs (of both the dung and rattlegrass varieties) into the newly enriched soil. The growth of rattlegrass within a stand that has been grazed (and defecated) over several times is far more vibrant than one that hasn't, due to the nitrogen-fixing actions of the bandersnatch's colon bacteria.

The dung beetles play a further role in maintaining this cycle. As they go about their business in the sauropats, they pick up the Saurorhizobium bacteria and their encysted spores. Sometimes, a beetle will fly onto or even into a grassbag's cloaca to feed on scraps of faeces, transporting the bacteria there as well. This is probably how young grassbags acquire the populations of Saurorhizobium that are so vital in maintaining the fields of grass.

The grassbags feed ravenously during the wet season, building huge reserves of fat and gaining up to six tonnes in weight. Great masses of adipose tissue collect on the dorsal fin, giving them a hump-backed appearance. The male bandersnatches acquire a striking blue-and-black striped head and soon the savannah shudders with the sounds of musth-ridden bulls trumpeting, battling rivals and seeking to mate with every receptive female in sight.

As the wet season begins to wane, mating ceases as good rattlegrass pastures become harder to find, forcing the grassbags collect in larger and larger congregations that overgraze and destroy the last few stands. These great combined herds of up to a hundred animals begin the long march towards reliable sources of water where they will wait out the dry season and lay their eggs. Those populations in the great rift valley have a fairly easy time, milling about in their thousands on the shores of the permanent lakes. Those in drier regions often have to make do with bare riverbeds where they must dig for seeps. A herd that fails to find water invariably perishes.

For the duration of the dry-spell, the sauropods will not feed nor move from the dry-season gathering area, surviving on their reserves of fat. The tissue in the dorsal hump is the first to go and within a month it has shriveled into a narrow sail. The dinosaurs face their fins away from the sun during the day and into the breeze at night, helping to stop their massive bodies from overheating.

One remarkable aspect of the bandersnatch's life cycle is that the eggs are timed to hatch at the height of the dry season. The females that mated in the previous year now deposit up to a hundred eggs in deep communal trenches at the heart of the gathering area. The eggs hatch in only three months and the metre long hatchlings spend the rest of the dry season growing within the cool shadows of the immense adults.

The young will instinctively crop at what little vegetation is available, including algae in the shallows. However, most of their nutrition comes from a creamy paste regurgitated by the adults. This mixture is siphoned from the fat reserves but it also contains samples of the adults' vital gastrointestinal flora which are soon transferred into the young. Any adult that has recently had a drink will spontaneously regurgitate onto the ground at the sound of hatchlings cheeping. Aside from this the adults show no sign of affection towards the young and probably do not recognize their own offspring from other hatchlings.

The strange breeding arrangement confers a number of advantages. The sauropods are now packed together in dense herds that form a daunting challenge to any marauding priscataur. The stress of the dry-season invariably leads to the death of several adults that soon leave the carnivores too preoccupied to bother with the hatchlings. The dry-season is the only time of year when the adults stay in one location and can thus confer protection to their offspring. It also frees them up to spend all their time feeding and mating during the bountiful rainy-season.

When the rains finally do arrive, the now badly emaciated adults disperse to seek out fresh pastures leaving the three metre long youngsters exposed and vulnerable. These form crèches and instinctively scramble for the nearest vegetative cover be it thorny scrub, reed beds or forest edge. For the next six years, the young lead a reclusive lifestyle, eating whatever they can reach and suffering heavy losses from predators and fire. Once they reach a length of nine metres, the survivors acquire the adults' more specialized feeding habits and head out onto the plains to join them.

- Brian Choo & Daniel Bensen

Copyright © 2003 Brian Choo & Daniel Bensen Graphic design by Matti Aumala, 2003