Compact Stonewort vs koala

Nitella tenuissima compared with Phascolarctos cinereus

Key Differences

• Compact Stonewort is Extinct while koala is Vulnerable.

Taxonomic Classification

Rank	Compact Stonewort	koala
Kingdom	Plantae (植物)	Animalia (动物界)
Phylum	Charophyta (轮藻门)	Chordata (脊索动物门)
Class	Charophyceae (輪藻綱)	Mammalia (哺乳動物)
Order	Charales (轮藻目)	Diprotodontia (雙門齒目)
Family	Characeae	Phascolarctidae (Koalas)
Genus	Nitella	Phascolarctos (Koalas)
Species	Nitella tenuissima	Phascolarctos cinereus

Conservation Status

Compact Stonewort

EX — Extinct

koala

VU — Vulnerable

Population: ~100.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Compact Stonewort	koala
Diet	—	Herbivore
Average Lifespan	—	15 years
Average Length	—	75 cm
Average Weight	—	10.0 kg

Habitat & Geographic Range

Compact Stonewort

Habitat

Native to Asia and Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Norway, Sweden, Taiwan, and United States.

koala

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Found in Australia. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Compact Stonewort

<em>Nitella tenuissima</em>, a stonewort formerly found in fresh and brackish water habitats, was a member of the charophyte family Characeae — the algal lineage most closely related to land plants. Historical records document its occurrence across Brazil, Norway, Sweden, Taiwan, and the United States, where it inhabited clear, oligotrophic lakes, ponds, and slow-flowing water bodies with low nutrient levels. Like other Nitella species, it was a delicate, translucent, submerged aquatic plant lacking the calcium carbonate encrustation of related genera, forming low-growing mats on soft sediments in well-illuminated shallow water. The species played a role in aquatic ecosystems by stabilising lake sediments, contributing to water clarity, and providing microhabitat for invertebrates and small aquatic organisms. <em>Nitella tenuissima</em> is classified as Extinct by the IUCN, having not been recorded from any of its former localities despite targeted searches. The primary causes of its extinction are believed to be widespread eutrophication of freshwater habitats driven by agricultural nutrient runoff and sewage discharge, which eliminated the clear, nutrient-poor conditions on which the species depended. The loss of this stonewort is emblematic of the broader decline of freshwater charophyte diversity across the Northern Hemisphere. Biological traits including historical morphological measurements and reproductive parameters are documented only in sparse historical herbarium specimens and early botanical literature.

koala

澳大利亚东部和东南部的标志性有袋类动物，体重最大可达15千克，为了节省低热量桉树叶食物所提供的能量，每天最多睡眠22小时。高度特化，能够处理会致大多数其他哺乳动物死亡的有毒桉树成分，拥有专门适应解毒功能的肠道微生物群。因衣原体病、栖息地开发和气候变化导致种群锐减，2022年被列为濒危物种。