After 168 years without its original physical reference, the first animal ever officially named has a body again. Scientists have designated a modern specimen of the orb weaving spider Araneus angulatus as the species’ neotype.

First formally described in 1757, A. angulatus occupies a remarkable place in zoological naming. Yet the specimens behind that description, known as the type series, disappeared, leaving the scientific name without the physical anchor intended to define it.

The new specimen was collected on an island off the coast of Sweden, as close as practicable to where the originals were gathered more than 250 years ago. Its designation restores a tangible reference for a common European species whose name had become ambiguous in scientific communication.

“The most important reason [to name a new type] is that more than one valid scientific species is called A. angulatus,” study author and Smithsonian curator Jonathan Coddington told IFLScience.

Coddington said, “So, when one uses the name to communicate, nobody knows which species you are talking about. It is vitally important that scientific communication be accurate, and the type specimen system ensures that.”

The naming system that uses two parts, as in Homo sapiens, can be traced back almost 300 years to Swedish naturalist Carl Linnaeus. Frustrated by inconsistent naming systems for plants, Linnaeus sought to standardize the process and published Systema Naturae in 1735.

Another naturalist, Carl Alexander Clerck, turned his attention to animals. Clerck is thought to have been influenced by Linnaeus after attending one of his lectures in 1739, and he later collected and categorized spiders.

Clerck published Svenska Spindlar, a monograph on Swedish arachnids, in 1757. When Linnaeus updated Systema Naturae with animals the following year, he adopted many of the names Clerck had already given to 66 spider species.

The 10th edition of Systema Naturae, published in 1758, is often treated as the starting point for the modern naming system for animals. Because Clerck’s spider names appeared one year earlier, A. angulatus became the first officially named animal.

What happened to Clerck’s specimens remains mysterious. After his death in 1765, his widow sold the collection to Peter Jonas Bergius, who later donated it to the Bergius Botanical Garden in Stockholm.

The spiders were last seen there in 1858 by Tamerlan Thorell, according to Coddington. When the collection was examined in 1965, Clerck’s type series of three A. angulatus specimens was gone, and nobody knew how it had disappeared.

Type specimens give scientists a physical representation of a named species. If researchers believe they have discovered a related species, they can compare it with that reference, although differences between males and females can complicate the choice of a representative specimen.

Time can also threaten these collections as biological material breaks down or specimens are moved. Major events can destroy them as well, as happened with the original Spinosaurus fossils.

“There are well more than 2 million described species, and each one ought to have a physical type specimen, because the physical type neatly defines the meaning of the name,” Coddington told IFLScience. Designating a type for every new species became mandatory only in 1999.

To choose a neotype, the researchers followed the official rules governing zoological names. Those rules require evidence that a replacement specimen came as nearly as practicable from the original type locality.

“We specifically sought out Raul Vicente, a Swedish naturalist who knew where a population of A. angulatus lived. Raul collected eight animals, and we chose an adult male because male spiders are usually more taxonomically definitive than females.”

The researchers have now published the designation, reconnecting the historic name with a physical specimen. Coddington said Clerck’s other 65 spider types were also likely lost, but limited ambiguity about those species means the need for neotypes may be less pressing.

The new paper was published in the journal Taxonomy. For A. angulatus, the first officially named animal now once again has a specimen carrying its name.