Entry Category: Science and Technology - Starting with T

Tarantulas are the largest spiders in Arkansas and are among the most recognizable. Tarantulas are relative newcomers to Arkansas, having arrived in the state about 8,000 years ago. At that time, the climate of North America was much warmer and drier than it is today. Because of higher temperatures and lower amounts of rainfall, habitats more typical of the southwestern United States and the Great Plains expanded eastward into Arkansas and Missouri. Along with drier habitats came many of the animals associated with them, such as tarantulas and scorpions. As the climate became cooler and wetter about 4,000 years ago, these species did not retreat west. Instead, they became isolated within suitable patches of open, dry habitat surrounded by increasing …

Tardigrades (sometimes called water bears or moss piglets) are microscopic members of the Phylum Tardigrada, numbering more than sixty-seven subspecies, 1,018 species, four subgenera, 105 genera, fifteen subfamilies, twenty families, five orders, and three classes. Of these, there are fifty-four genera and 380 species known from the Americas, 245 species from the Nearctic ecozone, and 251 in the Neotropical ecozone. Several species of tardigrades can be found in Arkansas. Discovered in 1773 by the German entomologist and pastor Johann August Ephraim Goeze (1731–1793), they were nicknamed “water bears” because of their plump, bear-like appearance; legs with claws; and slow, lumbering gait. The name Tardigrada (“slow steppers”) was given in 1777 by the Italian Catholic priest, biologist, and physiologist Lazzaro Spallanzani …

The temperate basses are freshwater, brackish water, and marine species belonging to the Order Perciformes and Family Moronidae. They are represented by two genera and six species—the North American and northern African Morone (four species) and European Dicentrarchus (two species). In North America, two popular freshwater game fish species, white bass (Morone chrysops) and yellow bass (M. mississippiensis), are native, whereas two others, the anadromous striped bass (M. saxatilis) and brackish water white perch (M. americana), have been successfully introduced into several U.S. states. In Arkansas, M. chrysops, M. mississippiensis, M. saxatilis and, rarely, M. americana are found in various watersheds. In addition, hybrid M. saxatilis × M. chrysops have been cultured and stocked in several Arkansas reservoirs. Morphologically, in …

Termites belong to the Phylum Arthropoda, Class Insecta, Infraorder Isoptera, and Order Blattodea. They were formerly placed in a separate order (Isoptera) from the cockroaches (Blattodea), but Isoptera is currently classified at the taxonomic rank of infraorder. About 3,106 species are currently described within twelve families, with a few hundred more to still be described. There are several species of termites in Arkansas. Termites are among the most successful groups of insects on Earth, colonizing all continents except Antarctica. Comparatively speaking, the diversity of termite species is rather low in North America and Europe (fifty species are known from North America, and only ten species occur in Europe), but it is higher in South America, where over 400 species are …

Ruth Harris Thomas was a highly regarded amateur ornithologist whose column on birding in Arkansas was published by the Arkansas Gazette for about forty years. Her column not only documented area birds, but it also contributed to a growing appreciation for birds, birding, and habitat conservation. Ruth Harris was born in Kentucky on August 25, 1900, to Charles O. Harris and Columbia B. Cox Harris. She had two brothers. Majoring in English and journalism, Harris graduated from Louisiana State University in 1923, where she also edited the student newspaper. She moved to Little Rock (Pulaski County) in the autumn of 1923 to work as a reporter for the Arkansas Gazette newspaper. In 1927, she married Maine native Stanley Powers Rowland …

Thrips belong to the Phylum Arthropoda, Class Insecta, and Order Thysanoptera. They are minute (most are less than 1 mm long), slender insects with fringed wings and distinctive asymmetrical mouthparts. There are currently over 7,700 species-groups of recognized thrips, grouped into 780 extant and fifty-eight fossil genera. The traditional classification of the order recognizes nine families for extant species (plus five fossil families), with two subfamilies in the Phlaeothripidae (the only family in suborder Tubulifera) and four subfamilies in the Thripidae (one of eight families comprising suborder Terebrantia). The earliest recorded mention of thrips is from the seventeenth century and was a sketch made in 1691 by an Italian Jesuit scholar, Philippo Bonanni (1628‒1723). In 1744, the Swedish entomologist Baron …

Ticks belong to the phylum Arthropoda, class Arachnida, subclass Acari, suborder Parasitiformes, and order Ixodida (Metastigmata), which includes almost 900 recognized species. There are three families: Ixodidae, or the “hard” ticks (approximately 700 species); Argasidae, or the “soft” ticks (approximately 200 species); and Nuttalliellidae, containing only a single species, Nuttalliella namaqua, a tick found only in southern Africa. In Arkansas, nine genera and a total of nineteen species (three argasids and sixteen ixodids) are known. Another species, Rhipicephalus (Boophilus) annulatus, has been extirpated from Arkansas. Ticks are a highly specialized group of obligate, bloodsucking, nonpermanent ectoparasitic arthropods of vertebrates (mostly on reptiles, birds, and mammals) and are distributed throughout the world. In addition to being irritating to hosts and causing …

Topminnows belong to the Family Fundulidae, Order Cypriniformes, and Class Actinopterygii. This family also includes some North American killifishes. There are approximately forty-four to forty-six species that are found in the lowlands of North and Central America from southeastern Canada to the Yucatan Peninsula of Mexico, including the Mississippi River drainage, and the islands of Bermuda and Cuba. Most (forty species) of topminnows belong to the genus Fundulus, and others are included in the genera Lucania (three species) and Leptolucania (a single species). The Family Fundulidae is a paraphyletic grouping of members of genera Fundulus and Lucania. There are six species of topminnows found in Arkansas. Topminnows occur in both freshwater and marine waters as well as brackish environments. They …

The tornado season of 1952 was a particularly eventful one throughout the state. Twenty-six tornadoes were reported to have touched down in Arkansas from January to November that year. While twenty-six is well below the modern average of about thirty-nine tornadoes per year in Arkansas, an unusually large number of these storms in 1952 were EF-3 and stronger on the Enhanced Fujita Scale used to rate the strength of tornadoes (the ratings go from EF-0 to EF-5). Of the twenty-six tornadoes in this outbreak, at least five were rated EF-4. Among these tornadoes, the most deadly and most widely reported was the March 21, 1952, EF-4 tornado that struck White County on March 21. Over the course of the year, …

The tornado outbreak of March 1, 1997, was one of the deadliest in the history of the state of Arkansas. Sixteen tornadoes tracked across the state, killing twenty-five Arkansans. Several of the tornadoes had unusually long tracks, traveling between fifty and seventy-five miles. There was also a higher than statistically expected number of tornadoes of F3 strength or higher—that is, tornadoes with wind speeds in excess of 158 miles per hour. Of the sixteen tornadoes, four were responsible for all fatalities in the state, as well as much of the property damage. All sixteen tornadoes were produced by four supercell thunderstorms, with the four killer tornadoes being spawned from two such storms that formed ahead of a cold front. The …

Tornadoes—destructive, violently spinning vortices of air extending from high within severe thunderstorms to the surface of the earth—are more common in the United States than anywhere else on the planet. They are particularly prevalent in the area known as “Tornado Alley,” where the proper ingredients come together: a combination of warm, moist air from the Gulf of Mexico pulled northward by storm systems dragging strong continental cold air from Canada. While Arkansas is not normally included on maps of the infamous Tornado Alley, which is usually considered to stretch from north Texas northward through Oklahoma, Kansas, and Nebraska, the state has suffered many devastating tornado outbreaks. In January 1999, Arkansas recorded the most tornadoes on any individual January day in …

When European explorers first came to Arkansas in the sixteenth century, they found the vast majority of the state covered by some type of forest or woodland. In general, the upland areas of the state were covered by short-leaf pine/oak/hickory forests in areas underlain by acidic rocks (primarily sandstone and chert) and by oak/hickory forests in areas underlain by neutral to calcareous rocks (primarily limestone and dolomite). Lowland areas of eastern and southern Arkansas were covered primarily by bottomland hardwood forests, with bald-cypress/water-tupelo swamps in the wettest areas. The Gulf Coastal Plain of southern Arkansas was covered by a mix of forest types, with loblolly and/or short-leaf pine dominant in many areas. Within these general forest types were hundreds of …

Trematodes (flukes) include parasitic flatworms belonging to the phylum Platyhelminthes, class Trematoda, and subclasses Aspidogastrea (two orders, four families) and Digenea (ten orders, more than seventy-two families). The class numbers between 18,000 and 24,000 species; they are found primarily in a variety of animals, including humans and other vertebrates. Modern phylogenetic analysis reveals that the worms of class Monogenoidea (monogenetic flukes) are no longer included within the Trematoda and are more closely related to tapeworms. The modern mobility of human beings, combined with the international transportation of animals and foodstuffs that can be infected, means that diagnoses can occur well outside the areas where trematode species are endemic. However, while trematodes do occur in Arkansas, they do not pose a …

As defined by the National Hurricane Center, a tropical cyclone is a “rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has a closed low-level circulation.” Types of tropical cyclones are classified in terms of wind speed: A tropical depression is a tropical cyclone with maximum sustained winds of 38 miles per hour (mph) or lower. A tropical storm is a tropical cyclone with maximum sustained winds of 39 to 73 mph. A hurricane is a tropical cyclone with maximum sustained winds of 74 mph or higher. A major hurricane is tropical cyclone with maximum sustained winds of 111 mph or higher. Given the landlocked, central location of the state of Arkansas, it may …

Turpentine Creek Wildlife Refuge near Eureka Springs (Carroll County) is a 501(c)(3) nonprofit organization providing lifetime homes for abandoned, abused, and neglected big cats and other endangered wildlife. With over 450 acres and more than 120 exotic cats, the refuge is one of the largest big cat sanctuaries in North America licensed by the U.S. Department of Agriculture (USDA). The sanctuary is rated a “Must See” attraction by the Arkansas Department of Parks and Tourism and is one of the most popular destinations in the Eureka Springs area. Don Jackson, a former employee of the Dallas Zoo, along with his wife, Hilda, and their daughter, Tanya Smith, founded the refuge in 1992. After a friend acquired a lion cub and realized …