Lycopsis

Lycopsis is an extinct genus of South American metatherian that lived during the Miocene in Argentina and Colombia.^[1]

Lycopsis Temporal range: Mid-Late Miocene (Santacrucian-Chasicoan) ~16.3–9.0 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil of L. longirostrus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Sparassodonta
Superfamily:	†Borhyaenoidea
Genus:	†Lycopsis Cabrera 1927
Type species
†Lycopsis torresi Cabrera 1927
Other Species
L. longirostrus Marshall 1976 L. viverensis Forasiepi et al. 2003
Synonyms
Anatherium oxyrhynchus Ameghino 1894

History

Although not named until 1927, Florentino Ameghino described a species now seen as synonymous with Lycopsis torresi, Anatherium oxyrhynchus, in 1895 based on a mandibular ramus with several teeth.^[2][3] The fossil was recovered from Puesto Estancia La Costa in Santa Cruz, Argentina, dating to the Miocene.^[3] The type material of Lycopsis was collected in July 1895 by "C. Berry" from the middle Miocene strata of the Santa Cruz Formation along the Santa Cruz River in the same area.^[2][4] The fossils (MLP 11–113) were fragmentary, constituting only several fragmentary jaw sections from the maxilla and mandible, including several molars.^[4][5] However, these fossils were not named until in 1927, Ángel Cabrera named Lycopsis torresi, the generic name meaning "wolf-like aspect" after the anatomy of the mandible and the specific name after Argentine paleontologist and the director of the Museo de la Plata at the time, Luis Maria Torres.^[4]

Taxonomy

Skull of Lycopsis

The cladogram after the analysis of Suárez et al., 2015, looks as follows:^[6]

Sparassodonta	Patene Hondadelphys Stylocynus Hathliacynidae Acyon Cladosictis Sipalocyon Notogale Sallacyon Borhyaenoidea Lycopsis Lycopsis longirostrus Lycopsis viverensis Lycopsis torresi Lycopsis padillai Prothylacynus Pharsophorus Borhyaenidae Borhyaena Australohyaena Arctodictis sinclairi Arctodictis munizi Callistoe Paraborhyaena Thylacosmilidae Patagosmilus Thylacosmilus

Description

L. longirostrus weighed 15 kg (33 lb) and stood 35 cm (1 ft 2 in) at the shoulders.^[7] L. padilli slightly larger, weighing around 22 kg (49 lb), making this species the largest mammalian predator of its time.^[8]

Distribution and Habitat

Fossils of Lycopsis have been found in:^[3]

• Arroyo Chasicó Formation and Santa Cruz Formations, Argentina
• Honda Group, Colombia

Isotopic analysis suggests that L. viverensis lived less open environments compared to its distant relative,Thylacosmilus.^[9] On the other hand, L. longirostrus was believed to have inhabited in a densely forested habitat. This is further supported by the lack of the remains of terror birds.^[10][7]

Paleobiology

Predatory behavior

A 2004 study found the forelimbs of L. longirostrus weren’t adapted for frequent climbing and instead were better used for manipulating behavior such as foraging and feeding.^[10] Carbon isotope values suggests L. viverensis may have preyed upon rodents such as Cardiatherium and Tetrastylus and the litoperns Cullinia and Theosodon.^[11]